Methods and compositions for diagnosis and prognosis of renal injury and renal failure

ABSTRACT

The present invention relates to methods and compositions for monitoring, diagnosis, prognosis, and determination of treatment regimens in subjects suffering from or suspected of having a renal injury. In particular, the invention relates to using a one or more assays configured to detect a kidney injury marker selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 as diagnostic and prognostic biomarkers in renal injuries.

The present application claims priority to U.S. Provisional Patent Application No. 61/302,021 filed Feb. 5, 2010; U.S. Provisional Patent Application No. 61/302,025 filed Feb. 5, 2010; U.S. Provisional Patent Application No. 61/302,026 filed Feb. 5, 2010; U.S. Provisional Patent Application No. 61/302,027 filed Feb. 5, 2010; U.S. Provisional Patent Application No. 61/302,036 filed Feb. 5, 2010; and U.S. Provisional Patent Application No. 61/374,060 filed Aug. 16, 2010, each of which is hereby incorporated in its entirety including all tables, figures, and claims.

BACKGROUND OF THE INVENTION

The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.

The kidney is responsible for water and solute excretion from the body. Its functions include maintenance of acid-base balance, regulation of electrolyte concentrations, control of blood volume, and regulation of blood pressure. As such, loss of kidney function through injury and/or disease results in substantial morbidity and mortality. A detailed discussion of renal injuries is provided in Harrison's Principles of Internal Medicine, 17^(th) Ed., McGraw Hill, New York, pages 1741-1830, which are hereby incorporated by reference in their entirety. Renal disease and/or injury may be acute or chronic. Acute and chronic kidney disease are described as follows (from Current Medical Diagnosis & Treatment 2008, 47^(th) Ed, McGraw Hill, New York, pages 785-815, which are hereby incorporated by reference in their entirety): “Acute renal failure is worsening of renal function over hours to days, resulting in the retention of nitrogenous wastes (such as urea nitrogen) and creatinine in the blood. Retention of these substances is called azotemia. Chronic renal failure (chronic kidney disease) results from an abnormal loss of renal function over months to years”.

Acute renal failure (ARF, also known as acute kidney injury, or AKI) is an abrupt (typically detected within about 48 hours to 1 week)reduction in glomerular filtration. This loss of filtration capacity results in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney, a reduction in urine output, or both. It is reported that ARF complicates about 5% of hospital admissions, 4-15% of cardiopulmonary bypass surgeries, and up to 30% of intensive care admissions. ARF may be categorized as prerenal, intrinsic renal, or postrenal in causation. Intrinsic renal disease can be further divided into glomerular, tubular, interstitial, and vascular abnormalities. Major causes of ARF are described in the following table, which is adapted from the Merck Manual, 17^(th) ed., Chapter 222, and which is hereby incorporated by reference in their entirety:

Type Risk Factors Prerenal ECF volume depletion Excessive diuresis, hemorrhage, GI losses, loss of intravascular fluid into the extravascular space (due to ascites, peritonitis, pancreatitis, or burns), loss of skin and mucus membranes, renal salt- and water-wasting states Low cardiac output Cardiomyopathy, MI, cardiac tamponade, pulmonary embolism, pulmonary hypertension, positive-pressure mechanical ventilation Low systemic vascular Septic shock, liver failure, antihypertensive drugs resistance Increased renal vascular NSAIDs, cyclosporines, tacrolimus, hypercalcemia, resistance anaphylaxis, anesthetics, renal artery obstruction, renal vein thrombosis, sepsis, hepatorenal syndrome Decreased efferent ACE inhibitors or angiotensin II receptor blockers arteriolar tone (leading to decreased GFR from reduced glomerular transcapillary pressure, especially in patients with bilateral renal artery stenosis) Intrinsic Renal Acute tubular injury Ischemia (prolonged or severe prerenal state): surgery, hemorrhage, arterial or venous obstruction; Toxins: NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, streptozotocin Acute glomerulonephritis ANCA-associated: Crescentic glomerulonephritis, polyarteritis nodosa, Wegener's granulomatosis; Anti- GBM glomerulonephritis: Goodpasture's syndrome; Immune-complex: Lupus glomerulonephritis, postinfectious glomerulonephritis, cryoglobulinemic glomerulonephritis Acute tubulointerstitial Drug reaction (eg, β-lactams, NSAIDs, sulfonamides, nephritis ciprofloxacin, thiazide diuretics, furosemide, phenytoin, allopurinol, pyelonephritis, papillary necrosis Acute vascular Vasculitis, malignant hypertension, thrombotic nephropathy microangiopathies, scleroderma, atheroembolism Infiltrative diseases Lymphoma, sarcoidosis, leukemia Postrenal Tubular precipitation Uric acid (tumor lysis), sulfonamides, triamterene, acyclovir, indinavir, methotrexate, ethylene glycol ingestion, myeloma protein, myoglobin Ureteral obstruction Intrinsic: Calculi, clots, sloughed renal tissue, fungus ball, edema, malignancy, congenital defects; Extrinsic: Malignancy, retroperitoneal fibrosis, ureteral trauma during surgery or high impact injury Bladder obstruction Mechanical: Benign prostatic hyperplasia, prostate cancer, bladder cancer, urethral strictures, phimosis, paraphimosis, urethral valves, obstructed indwelling urinary catheter; Neurogenic: Anticholinergic drugs, upper or lower motor neuron lesion

In the case of ischemic ARF, the course of the disease may be divided into four phases. During an initiation phase, which lasts hours to days, reduced perfusion of the kidney is evolving into injury. Glomerular ultrafiltration reduces, the flow of filtrate is reduced due to debris within the tubules, and back leakage of filtrate through injured epithelium occurs. Renal injury can be mediated during this phase by reperfusion of the kidney. Initiation is followed by an extension phase which is characterized by continued ischemic injury and inflammation and may involve endothelial damage and vascular congestion. During the maintenance phase, lasting from 1 to 2 weeks, renal cell injury occurs, and glomerular filtration and urine output reaches a minimum. A recovery phase can follow in which the renal epithelium is repaired and GFR gradually recovers. Despite this, the survival rate of subjects with ARF may be as low as about 60%.

Acute kidney injury caused by radiocontrast agents (also called contrast media) and other nephrotoxins such as cyclosporine, antibiotics including aminoglycosides and anticancer drugs such as cisplatin manifests over a period of days to about a week. Contrast induced nephropathy (CIN, which is AKI caused by radiocontrast agents) is thought to be caused by intrarenal vasoconstriction (leading to ischemic injury) and from the generation of reactive oxygen species that are directly toxic to renal tubular epithelial cells. CIN classically presents as an acute (onset within 24-48h) but reversible (peak 3-5 days, resolution within 1 week) rise in blood urea nitrogen and serum creatinine.

A commonly reported criteria for defining and detecting AKI is an abrupt (typically within about 2-7 days or within a period of hospitalization) elevation of serum creatinine. Although the use of serum creatinine elevation to define and detect AKI is well established, the magnitude of the serum creatinine elevation and the time over which it is measured to define AKI varies considerably among publications. Traditionally, relatively large increases in serum creatinine such as 100%, 200%, an increase of at least 100% to a value over 2 mg/dL and other definitions were used to define AKI. However, the recent trend has been towards using smaller serum creatinine rises to define AKI. The relationship between serum creatinine rise, AKI and the associated health risks are reviewed in Praught and Shlipak, Curr Opin Nephrol Hypertens 14:265-270, 2005 and Chertow et al, J Am Soc Nephrol 16: 3365-3370, 2005, which, with the references listed therein, are hereby incorporated by reference in their entirety. As described in these publications, acute worsening renal function (AKI) and increased risk of death and other detrimental outcomes are now known to be associated with very small increases in serum creatinine. These increases may be determined as a relative (percent) value or a nominal value. Relative increases in serum creatinine as small as 20% from the pre-injury value have been reported to indicate acutely worsening renal function (AKI) and increased health risk, but the more commonly reported value to define AKI and increased health risk is a relative increase of at least 25%. Nominal increases as small as 0.3 mg/dL, 0.2 mg/dL or even 0.1 mg/dL have been reported to indicate worsening renal function and increased risk of death. Various time periods for the serum creatinine to rise to these threshold values have been used to define AKI, for example, ranging from 2 days, 3 days, 7 days, or a variable period defined as the time the patient is in the hospital or intensive care unit. These studies indicate there is not a particular threshold serum creatinine rise (or time period for the rise) for worsening renal function or AKI, but rather a continuous increase in risk with increasing magnitude of serum creatinine rise.

One study (Lassnigg et all, J Am Soc Nephrol 15:1597-1605, 2004, hereby incorporated by reference in its entirety) investigated both increases and decreases in serum creatinine. Patients with a mild fall in serum creatinine of −0.1 to −0.3 mg/dL following heart surgery had the lowest mortality rate. Patients with a larger fall in serum creatinine (more than or equal to −0.4 mg/dL) or any increase in serum creatinine had a larger mortality rate. These findings caused the authors to conclude that even very subtle changes in renal function (as detected by small creatinine changes within 48 hours of surgery) seriously effect patient's outcomes. In an effort to reach consensus on a unified classification system for using serum creatinine to define AKI in clinical trials and in clinical practice, Bellomo et al., Crit. Care. 8(4):R204-12, 2004, which is hereby incorporated by reference in its entirety, proposes the following classifications for stratifying AKI patients:

“Risk”: serum creatinine increased 1.5 fold from baseline OR urine production of <0.5 ml/kg body weight/hr for 6 hours; “Injury”: serum creatinine increased 2.0 fold from baseline OR urine production <0.5 ml/kg/hr for 12 h; “Failure”: serum creatinine increased 3.0 fold from baseline OR creatinine >355 μmol/l (with a rise of >44) or urine output below 0.3 ml/kg/hr for 24 h or anuria for at least 12 hours; And included two clinical outcomes: “Loss”: persistent need for renal replacement therapy for more than four weeks. “ESRD”: end stage renal disease—the need for dialysis for more than 3 months.

These criteria are called the RIFLE criteria, which provide a useful clinical tool to classify renal status. As discussed in Kellum, Crit. Care Med. 36: S141-45, 2008 and Ricci et al., Kidney Int. 73, 538-546, 2008, each hereby incorporated by reference in its entirety, the RIFLE criteria provide a uniform definition of AKI which has been validated in numerous studies.

More recently, Mehta et al., Crit. Care 11:R31 (doi:10.1186.cc5713), 2007, hereby incorporated by reference in its entirety, proposes the following similar classifications for stratifying AKI patients, which have been modified from RIFLE:

“Stage I”: increase in serum creatinine of more than or equal to 0.3 mg/dL (>26.4 μmol/L) or increase to more than or equal to 150% (1.5-fold) from baseline OR urine output less than 0.5 mL/kg per hour for more than 6 hours; “Stage II”: increase in serum creatinine to more than 200% (>2-fold) from baseline OR urine output less than 0.5 mL/kg per hour for more than 12 hours; “Stage III”: increase in serum creatinine to more than 300% (>3-fold) from baseline OR serum creatinine ≧354 μmol/L accompanied by an acute increase of at least 44 μmol/L OR urine output less than 0.3 mL/kg per hour for 24 hours or anuria for 12 hours.

The CIN Consensus Working Panel (McCollough et al, Rev Cardiovasc Med. 2006; 7(4): 177-197, hereby incorporated by reference in its entirety) uses a serum creatinine rise of 25% to define Contrast induced nephropathy (which is a type of AKI).Although various groups propose slightly different criteria for using serum creatinine to detect AKI, the consensus is that small changes in serum creatinine, such as 0.3 mg/dL or 25%, are sufficient to detect AKI (worsening renal function) and that the magnitude of the serum creatinine change is an indicator of the severity of the AKI and mortality risk.

Although serial measurement of serum creatinine over a period of days is an accepted method of detecting and diagnosing AKI and is considered one of the most important tools to evaluate AKI patients, serum creatinine is generally regarded to have several limitations in the diagnosis, assessment and monitoring of AKI patients. The time period for serum creatinine to rise to values (e.g., a 0.3 mg/dL or 25% rise) considered diagnostic for AKI can be 48 hours or longer depending on the definition used. Since cellular injury in AKI can occur over a period of hours, serum creatinine elevations detected at 48 hours or longer can be a late indicator of injury, and relying on serum creatinine can thus delay diagnosis of AKI. Furthermore, serum creatinine is not a good indicator of the exact kidney status and treatment needs during the most acute phases of AKI when kidney function is changing rapidly. Some patients with AKI will recover fully, some will need dialysis (either short term or long term) and some will have other detrimental outcomes including death, major adverse cardiac events and chronic kidney disease. Because serum creatinine is a marker of filtration rate, it does not differentiate between the causes of AKI (pre-renal, intrinsic renal, post-renal obstruction, atheroembolic, etc) or the category or location of injury in intrinsic renal disease (for example, tubular, glomerular or interstitial in origin). Urine output is similarly limited, Knowing these things can be of vital importance in managing and treating patients with AKI.

These limitations underscore the need for better methods to detect and assess AKI, particularly in the early and subclinical stages, but also in later stages when recovery and repair of the kidney can occur. Furthermore, there is a need to better identify patients who are at risk of having an AKI.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to provide methods and compositions for evaluating renal function in a subject. As described herein, measurement of one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 (each referred to herein as a “kidney injury marker”) can be used for diagnosis, prognosis, risk stratification, staging, monitoring, categorizing and determination of further diagnosis and treatment regimens in subjects suffering or at risk of suffering from an injury to renal function, reduced renal function, and/or acute renal failure (also called acute kidney injury).

The kidney injury markers of the present invention may be used, individually or in panels comprising a plurality of kidney injury markers, for risk stratification (that is, to identify subjects at risk for a future injury to renal function, for future progression to reduced renal function, for future progression to ARF, for future improvement in renal function, etc.); for diagnosis of existing disease (that is, to identify subjects who have suffered an injury to renal function, who have progressed to reduced renal function, who have progressed to ARF, etc.); for monitoring for deterioration or improvement of renal function; and for predicting a future medical outcome, such as improved or worsening renal function, a decreased or increased mortality risk, a decreased or increased risk that a subject will require renal replacement therapy (i.e., hemodialysis, peritoneal dialysis, hemofiltration, and/or renal transplantation, a decreased or increased risk that a subject will recover from an injury to renal function, a decreased or increased risk that a subject will recover from ARF, a decreased or increased risk that a subject will progress to end stage renal disease, a decreased or increased risk that a subject will progress to chronic renal failure, a decreased or increased risk that a subject will suffer rejection of a transplanted kidney, etc.

In a first aspect, the present invention relates to methods for evaluating renal status in a subject. These methods comprise performing an assay method that is configured to detect one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 is/are then correlated to the renal status of the subject. This correlation to renal status may include correlating the assay result(s) to one or more of risk stratification, diagnosis, prognosis, staging, classifying and monitoring of the subject as described herein. Thus, the present invention utilizes one or more kidney injury markers of the present invention for the evaluation of renal injury.

In certain embodiments, the methods for evaluating renal status described herein are methods for risk stratification of the subject; that is, assigning a likelihood of one or more future changes in renal status to the subject. In these embodiments, the assay result(s) is/are correlated to one or more such future changes. The following are preferred risk stratification embodiments.

In preferred risk stratification embodiments, these methods comprise determining a subject's risk for a future injury to renal function, and the assay result(s) is/are correlated to a likelihood of such a future injury to renal function. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of suffering a future injury to renal function is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of suffering a future injury to renal function is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

In other preferred risk stratification embodiments, these methods comprise determining a subject's risk for future reduced renal function, and the assay result(s) is/are correlated to a likelihood of such reduced renal function. For example, the measured concentrations may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of suffering a future reduced renal function is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of future reduced renal function is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

In still other preferred risk stratification embodiments, these methods comprise determining a subject's likelihood for a future improvement in renal function, and the assay result(s) is/are correlated to a likelihood of such a future improvement in renal function. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of a future improvement in renal function is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold. For a “negative going” kidney injury marker, an increased likelihood of a future improvement in renal function is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold.

In yet other preferred risk stratification embodiments, these methods comprise determining a subject's risk for progression to ARF, and the result(s) is/are correlated to a likelihood of such progression to ARF. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of progression to ARF is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of progression to ARF is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

And in other preferred risk stratification embodiments, these methods comprise determining a subject's outcome risk, and the assay result(s) is/are correlated to a likelihood of the occurrence of a clinical outcome related to a renal injury suffered by the subject. For example, the measured concentration(s) may each be compared to a threshold value. For a “positive going” kidney injury marker, an increased likelihood of one or more of: acute kidney injury, progression to a worsening stage of AKI, mortality, a requirement for renal replacement therapy, a requirement for withdrawal of renal toxins, end stage renal disease, heart failure, stroke, myocardial infarction, progression to chronic kidney disease, etc., is assigned to the subject when the measured concentration is above the threshold, relative to a likelihood assigned when the measured concentration is below the threshold. For a “negative going” kidney injury marker, an increased likelihood of one or more of: acute kidney injury, progression to a worsening stage of AKI, mortality, a requirement for renal replacement therapy, a requirement for withdrawal of renal toxins, end stage renal disease, heart failure, stroke, myocardial infarction, progression to chronic kidney disease, etc., is assigned to the subject when the measured concentration is below the threshold, relative to a likelihood assigned when the measured concentration is above the threshold.

In such risk stratification embodiments, preferably the likelihood or risk assigned is that an event of interest is more or less likely to occur within 180 days of the time at which the body fluid sample is obtained from the subject. In particularly preferred embodiments, the likelihood or risk assigned relates to an event of interest occurring within a shorter time period such as 18 months, 120 days, 90 days, 60 days, 45 days, 30 days, 21 days, 14 days, 7 days, 5 days, 96 hours, 72 hours, 48 hours, 36 hours, 24 hours, 12 hours, or less. A risk at 0 hours of the time at which the body fluid sample is obtained from the subject is equivalent to diagnosis of a current condition.

In preferred risk stratification embodiments, the subject is selected for risk stratification based on the pre-existence in the subject of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF. For example, a subject undergoing or having undergone major vascular surgery, coronary artery bypass, or other cardiac surgery; a subject having pre-existing congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, glomerular filtration below the normal range, cirrhosis, serum creatinine above the normal range, or sepsis; or a subject exposed to NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin are all preferred subjects for monitoring risks according to the methods described herein. This list is not meant to be limiting. By “pre-existence” in this context is meant that the risk factor exists at the time the body fluid sample is obtained from the subject. In particularly preferred embodiments, a subject is chosen for risk stratification based on an existing diagnosis of injury to renal function, reduced renal function, or ARF.

In other embodiments, the methods for evaluating renal status described herein are methods for diagnosing a renal injury in the subject; that is, assessing whether or not a subject has suffered from an injury to renal function, reduced renal function, or ARF. In these embodiments, the assay result(s), for example measured concentration(s) of one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 is/are correlated to the occurrence or nonoccurrence of a change in renal status. The following are preferred diagnostic embodiments.

In preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of an injury to renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of such an injury. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury to renal function is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury to renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury to renal function is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury to renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In other preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of reduced renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of an injury causing reduced renal function. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury causing reduced renal function is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury causing reduced renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury causing reduced renal function is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury causing reduced renal function may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In yet other preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of ARF, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of an injury causing ARF. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of ARF is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of ARF may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of ARF is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of ARF may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In still other preferred diagnostic embodiments, these methods comprise diagnosing a subject as being in need of renal replacement therapy, and the assay result(s) is/are correlated to a need for renal replacement therapy. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury creating a need for renal replacement therapy is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal replacement therapy may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury creating a need for renal replacement therapy is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal replacement therapy may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In still other preferred diagnostic embodiments, these methods comprise diagnosing a subject as being in need of renal transplantation, and the assay result (s0 is/are correlated to a need for renal transplantation. For example, each of the measured concentration(s) may be compared to a threshold value. For a positive going marker, an increased likelihood of the occurrence of an injury creating a need for renal transplantation is assigned to the subject when the measured concentration is above the threshold (relative to the likelihood assigned when the measured concentration is below the threshold); alternatively, when the measured concentration is below the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal transplantation may be assigned to the subject (relative to the likelihood assigned when the measured concentration is above the threshold). For a negative going marker, an increased likelihood of the occurrence of an injury creating a need for renal transplantation is assigned to the subject when the measured concentration is below the threshold (relative to the likelihood assigned when the measured concentration is above the threshold); alternatively, when the measured concentration is above the threshold, an increased likelihood of the nonoccurrence of an injury creating a need for renal transplantation may be assigned to the subject (relative to the likelihood assigned when the measured concentration is below the threshold).

In still other embodiments, the methods for evaluating renal status described herein are methods for monitoring a renal injury in the subject; that is, assessing whether or not renal function is improving or worsening in a subject who has suffered from an injury to renal function, reduced renal function, or ARF. In these embodiments, the assay result(s), for example measured concentration(s) of one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 is/are correlated to the occurrence or nonoccurrence of a change in renal status. The following are preferred monitoring embodiments.

In preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from an injury to renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In other preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from reduced renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In yet other preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from acute renal failure, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In other additional preferred monitoring embodiments, these methods comprise monitoring renal status in a subject at risk of an injury to renal function due to the pre-existence of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. For example, the measured concentration(s) may be compared to a threshold value. For a positive going marker, when the measured concentration is above the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is below the threshold, an improvement of renal function may be assigned to the subject. For a negative going marker, when the measured concentration is below the threshold, a worsening of renal function may be assigned to the subject; alternatively, when the measured concentration is above the threshold, an improvement of renal function may be assigned to the subject.

In still other embodiments, the methods for evaluating renal status described herein are methods for classifying a renal injury in the subject; that is, determining whether a renal injury in a subject is prerenal, intrinsic renal, or postrenal; and/or further subdividing these classes into subclasses such as acute tubular injury, acute glomerulonephritis acute tubulointerstitial nephritis, acute vascular nephropathy, or infiltrative disease; and/or assigning a likelihood that a subject will progress to a particular RIFLE stage. In these embodiments, the assay result(s), for example measured concentration(s) of one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 is/are correlated to a particular class and/or subclass. The following are preferred classification embodiments.

In preferred classification embodiments, these methods comprise determining whether a renal injury in a subject is prerenal, intrinsic renal, or postrenal; and/or further subdividing these classes into subclasses such as acute tubular injury, acute glomerulonephritis acute tubulointerstitial nephritis, acute vascular nephropathy, or infiltrative disease; and/or assigning a likelihood that a subject will progress to a particular RIFLE stage, and the assay result(s) is/are correlated to the injury classification for the subject. For example, the measured concentration may be compared to a threshold value, and when the measured concentration is above the threshold, a particular classification is assigned; alternatively, when the measured concentration is below the threshold, a different classification may be assigned to the subject.

A variety of methods may be used by the skilled artisan to arrive at a desired threshold value for use in these methods. For example, the threshold value may be determined from a population of normal subjects by selecting a concentration representing the 75^(th), 85^(th), 90^(th), 95^(th), or 99^(th) percentile of a kidney injury marker measured in such normal subjects. Alternatively, the threshold value may be determined from a “diseased” population of subjects, e.g., those suffering from an injury or having a predisposition for an injury (e.g., progression to ARF or some other clinical outcome such as death, dialysis, renal transplantation, etc.), by selecting a concentration representing the 75^(th), 85^(th), 90^(th), 95^(th), or 99^(th) percentile of a kidney injury marker measured in such subjects. In another alternative, the threshold value may be determined from a prior measurement of a kidney injury marker in the same subject; that is, a temporal change in the level of a kidney injury marker in the subject may be used to assign risk to the subject.

The foregoing discussion is not meant to imply, however, that the kidney injury markers of the present invention must be compared to corresponding individual thresholds. Methods for combining assay results can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, calculating ratios of markers, etc. This list is not meant to be limiting. In these methods, a composite result which is determined by combining individual markers may be treated as if it is itself a marker; that is, a threshold may be determined for the composite result as described herein for individual markers, and the composite result for an individual patient compared to this threshold.

The ability of a particular test to distinguish two populations can be established using ROC analysis. For example, ROC curves established from a “first” subpopulation which is predisposed to one or more future changes in renal status, and a “second” subpopulation which is not so predisposed can be used to calculate a ROC curve, and the area under the curve provides a measure of the quality of the test. Preferably, the tests described herein provide a ROC curve area greater than 0.5, preferably at least 0.6, more preferably 0.7, still more preferably at least 0.8, even more preferably at least 0.9, and most preferably at least 0.95.

In certain aspects, the measured concentration of one or more kidney injury markers, or a composite of such markers, may be treated as continuous variables. For example, any particular concentration can be converted into a corresponding probability of a future reduction in renal function for the subject, the occurrence of an injury, a classification, etc. In yet another alternative, a threshold that can provide an acceptable level of specificity and sensitivity in separating a population of subjects into “bins” such as a “first” subpopulation (e.g., which is predisposed to one or more future changes in renal status, the occurrence of an injury, a classification, etc.) and a “second” subpopulation which is not so predisposed. A threshold value is selected to separate this first and second population by one or more of the following measures of test accuracy:

an odds ratio greater than 1, preferably at least about 2 or more or about 0.5 or less, more preferably at least about 3 or more or about 0.33 or less, still more preferably at least about 4 or more or about 0.25 or less, even more preferably at least about 5 or more or about 0.2 or less, and most preferably at least about 10 or more or about 0.1 or less; a specificity of greater than 0.5, preferably at least about 0.6, more preferably at least about 0.7, still more preferably at least about 0.8, even more preferably at least about 0.9 and most preferably at least about 0.95, with a corresponding sensitivity greater than 0.2, preferably greater than about 0.3, more preferably greater than about 0.4, still more preferably at least about 0.5, even more preferably about 0.6, yet more preferably greater than about 0.7, still more preferably greater than about 0.8, more preferably greater than about 0.9, and most preferably greater than about 0.95; a sensitivity of greater than 0.5, preferably at least about 0.6, more preferably at least about 0.7, still more preferably at least about 0.8, even more preferably at least about 0.9 and most preferably at least about 0.95, with a corresponding specificity greater than 0.2, preferably greater than about 0.3, more preferably greater than about 0.4, still more preferably at least about 0.5, even more preferably about 0.6, yet more preferably greater than about 0.7, still more preferably greater than about 0.8, more preferably greater than about 0.9, and most preferably greater than about 0.95; at least about 75% sensitivity, combined with at least about 75% specificity; a positive likelihood ratio (calculated as sensitivity/(1-specificity)) of greater than 1, at least about 2, more preferably at least about 3, still more preferably at least about 5, and most preferably at least about 10; or a negative likelihood ratio (calculated as (1-sensitivity)/specificity) of less than 1, less than or equal to about 0.5, more preferably less than or equal to about 0.3, and most preferably less than or equal to about 0.1.

The term “about” in the context of any of the above measurements refers to +/−5% of a given measurement.

Multiple thresholds may also be used to assess renal status in a subject. For example, a “first” subpopulation which is predisposed to one or more future changes in renal status, the occurrence of an injury, a classification, etc., and a “second” subpopulation which is not so predisposed can be combined into a single group. This group is then subdivided into three or more equal parts (known as tertiles, quartiles, quintiles, etc., depending on the number of subdivisions). An odds ratio is assigned to subjects based on which subdivision they fall into. If one considers a tertile, the lowest or highest tertile can be used as a reference for comparison of the other subdivisions. This reference subdivision is assigned an odds ratio of 1. The second tertile is assigned an odds ratio that is relative to that first tertile. That is, someone in the second tertile might be 3 times more likely to suffer one or more future changes in renal status in comparison to someone in the first tertile. The third tertile is also assigned an odds ratio that is relative to that first tertile.

In certain embodiments, the assay method is an immunoassay. Antibodies for use in such assays will specifically bind a full length kidney injury marker of interest, and may also bind one or more polypeptides that are “related” thereto, as that term is defined hereinafter. Numerous immunoassay formats are known to those of skill in the art. Preferred body fluid samples are selected from the group consisting of urine, blood, serum, saliva, tears, and plasma.

The foregoing method steps should not be interpreted to mean that the kidney injury marker assay result(s) is/are used in isolation in the methods described herein. Rather, additional variables or other clinical indicia may be included in the methods described herein. For example, a risk stratification, diagnostic, classification, monitoring, etc. method may combine the assay result(s) with one or more variables measured for the subject selected from the group consisting of demographic information (e.g., weight, sex, age, race), medical history (e.g., family history, type of surgery, pre-existing disease such as aneurism, congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, or sepsis, type of toxin exposure such as NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin), clinical variables (e.g., blood pressure, temperature, respiration rate), risk scores (APACHE score, PREDICT score, TIMI Risk Score for UA/NSTEMI, Framingham Risk Score, risk scores of Thakar et al. (J. Am. Soc. Nephrol. 16: 162-68, 2005), Mehran et al. (J. Am. Coll. Cardiol. 44: 1393-99, 2004), Wijeysundera et al. (JAMA 297: 1801-9, 2007), Goldstein and Chawla (Clin. J. Am. Soc. Nephrol. 5: 943-49, 2010), or Chawla et al. (Kidney Intl. 68: 2274-80, 2005)), a glomerular filtration rate, an estimated glomerular filtration rate, a urine production rate, a serum or plasma creatinine concentration, a urine creatinine concentration, a fractional excretion of sodium, a urine sodium concentration, a urine creatinine to serum or plasma creatinine ratio, a urine specific gravity, a urine osmolality, a urine urea nitrogen to plasma urea nitrogen ratio, a plasma BUN to creatnine ratio, a renal failure index calculated as urine sodium/(urine creatinine/plasma creatinine), a serum or plasma neutrophil gelatinase (NGAL) concentration, a urine NGAL concentration, a serum or plasma cystatin C concentration, a serum or plasma cardiac troponin concentration, a serum or plasma BNP concentration, a serum or plasma NTproBNP concentration, and a serum or plasma proBNP concentration. Other measures of renal function which may be combined with one or more kidney injury marker assay result(s) are described hereinafter and in Harrison's Principles of Internal Medicine, 17^(th) Ed., McGraw Hill, New York, pages 1741-1830, and Current Medical Diagnosis & Treatment 2008, 47^(th) Ed, McGraw Hill, New York, pages 785-815, each of which are hereby incorporated by reference in their entirety.

When more than one marker is measured, the individual markers may be measured in samples obtained at the same time, or may be determined from samples obtained at different (e.g., an earlier or later) times. The individual markers may also be measured on the same or different body fluid samples. For example, one kidney injury marker may be measured in a serum or plasma sample and another kidney injury marker may be measured in a urine sample. In addition, assignment of a likelihood may combine an individual kidney injury marker assay result with temporal changes in one or more additional variables.

In various related aspects, the present invention also relates to devices and kits for performing the methods described herein. Suitable kits comprise reagents sufficient for performing an assay for at least one of the described kidney injury markers, together with instructions for performing the described threshold comparisons.

In certain embodiments, reagents for performing such assays are provided in an assay device, and such assay devices may be included in such a kit. Preferred reagents can comprise one or more solid phase antibodies, the solid phase antibody comprising antibody that detects the intended biomarker target(s) bound to a solid support. In the case of sandwich immunoassays, such reagents can also include one or more detectably labeled antibodies, the detectably labeled antibody comprising antibody that detects the intended biomarker target(s) bound to a detectable label. Additional optional elements that may be provided as part of an assay device are described hereinafter.

Detectable labels may include molecules that are themselves detectable (e.g., fluorescent moieties, electrochemical labels, ecl (electrochemical luminescence) labels, metal chelates, colloidal metal particles, etc.) as well as molecules that may be indirectly detected by production of a detectable reaction product (e.g., enzymes such as horseradish peroxidase, alkaline phosphatase, etc.) or through the use of a specific binding molecule which itself may be detectable (e.g., a labeled antibody that binds to the second antibody, biotin, digoxigenin, maltose, oligohistidine, 2,4-dintrobenzene, phenylarsenate, ssDNA, dsDNA, etc.).

Generation of a signal from the signal development element can be performed using various optical, acoustical, and electrochemical methods well known in the art. Examples of detection modes include fluorescence, radiochemical detection, reflectance, absorbance, amperometry, conductance, impedance, interferometry, ellipsometry, etc. In certain of these methods, the solid phase antibody is coupled to a transducer (e.g., a diffraction grating, electrochemical sensor, etc) for generation of a signal, while in others, a signal is generated by a transducer that is spatially separate from the solid phase antibody (e.g., a fluorometer that employs an excitation light source and an optical detector). This list is not meant to be limiting. Antibody-based biosensors may also be employed to determine the presence or amount of analytes that optionally eliminate the need for a labeled molecule.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to methods and compositions for diagnosis, differential diagnosis, risk stratification, monitoring, classifying and determination of treatment regimens in subjects suffering or at risk of suffering from injury to renal function, reduced renal function and/or acute renal failure through measurement of one or more kidney injury markers. In various embodiments, a measured concentration of one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 or one or more markers related thereto, are correlated to the renal status of the subject.

For purposes of this document, the following definitions apply:

As used herein, an “injury to renal function” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) measurable reduction in a measure of renal function. Such an injury may be identified, for example, by a decrease in glomerular filtration rate or estimated GFR, a reduction in urine output, an increase in serum creatinine, an increase in serum cystatin C, a requirement for renal replacement therapy, etc. “Improvement in Renal Function” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) measurable increase in a measure of renal function. Preferred methods for measuring and/or estimating GFR are described hereinafter.

As used herein, “reduced renal function” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) reduction in kidney function identified by an absolute increase in serum creatinine of greater than or equal to 0.1 mg/dL (≧8.8 μmol/L), a percentage increase in serum creatinine of greater than or equal to 20% (1.2-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour).

As used herein, “acute renal failure” or “ARF” is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) reduction in kidney function identified by an absolute increase in serum creatinine of greater than or equal to 0.3 mg/dl (>26.4 μ=1/1), a percentage increase in serum creatinine of greater than or equal to 50% (1. 5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour for at least 6 hours). This term is synonymous with “acute kidney injury” or “AKI.”

As used herein, the term “Coagulation factor VII” refers to one or more polypeptides present in a biological sample that are derived from the Coagulation factor VII precursor (human precursor: Swiss-Prot P08709 (SEQ ID NO: 1))

        10         20         30         40         50         60 MVSQALRLLC LLLGLQGCLA AGGVAKASGG ETRDMPWKPG PHRVFVTQEE AHGVLHRRRR         70         80         90        100        110        120 ANAFLEELRP GSLERECKEE QCSFEEAREI FKDAERTKLF WISYSDGDQC ASSPCQNGGS        130        140        150        160        170        180 CKDQLQSYIC FCLPAFEGRN CETHKDDQLI CVNENGGCEQ YCSDHTGTKR SCRCHEGYSL        190        200        210        220        230        240 LADGVSCTPT VEYPCGKIPI LEKRNASKPQ GRIVGGKVCP KGECPWQVLL LVNGAQLCGG        250        260        270        280        290        300 TLINTIWVVS AAHCFDKIKN WRNLIAVLGE HDLSEHDGDE QSRRVAQVII PSTYVPGTTN        310        320        330        340        350        360 HDIALLRLHQ PVVLTDHVVP LCLPERTFSE RTLAFVRFSL VSGWGQLLDR GATALELMVL        370        380        390        400        410        420 NVPRLMTQDC LQQSRKVGDS PNITEYMFCA GYSDGSKDSC KGDSGGPHAT HYRGTWYLTG        430        440        450        460 IVSWGQGCAT VGHFGVYTRV SQYIEWLQKL MRSEPRPGVL LRAPFP

The following domains have been identified in Coagulation factor VII:

Residues Length Domain ID  1-20 20 Signal peptide 21-60 40 Propeptide  61-212 152 Coagulation factor VII, light chain 213-466 254 Coagulation factor VII, heavy chain 22-43 22 Missing in Coagulation factor VII isoform B

As used herein, the term “CA19-9” (also called carbohydrate antigen 19-9 or sialylated Lewis (a) antigen) is a monosialoganglioside antigen found in patients with gastrointestinal adenocarcinoma. It is reportedly elevated in 21 to 42 percent of cases of gastric cancer, 20 to 40 percent of colon cancer, and 71 to 93 percent of pancreatic cancer. The main clinical use of CA19-9 is to see whether a pancreatic tumor is secreting it; if that is the case, then the levels should fall when the tumor is treated, and they may rise again if the disease recurs. In 5% of patients who lack the Lewis antigen, CA19-9 is not elevated in pancreatic cancer even with large tumors because they have a deficiency of a fucosyltransferase enzyme that is needed to produce CA19-9 as well as the Lewis antigen.

As used herein, the term “Insulin-like growth factor-binding protein 7” refers to one or more polypeptides present in a biological sample that are derived from the Insulin-like growth factor-binding protein 7 precursor (human precursor: Swiss-Prot Q16270 (SEQ ID NO: 2))

        10         20         30         40         50         60 MERPSLRALL LGAAGLLLLL LPLSSSSSSD TCGPCEPASC PPLPPLGCLL GETRDACGCC         70         80         90        100        110        120 PMCARGEGEP CGGGGAGRGY CAPGMECVKS RKRRKGKAGA AAGGPGVSGV CVCKSRYPVC        130        140        150        160        170        180 GSDGTTYPSG CQLRAASQRA ESRGEKAITQ VSKGTCEQGP SIVTPPKDIW NVTGAQVYLS        190        200        210        220        230        240 CEVIGIPTPV LIWNKVKRGH YGVQRTELLP GDRDNLAIQT RGGPEKHEVT GWVLVSPLSK        250        260        270        280 EDAGEYECHA SNSQGQASAS AKITVVDALH EIPVKKGEGA EL

The following domains have been identified in Insulin-like growth factor-binding protein 7:

Residues Length Domain ID 1-26 26 Signal peptide 27-282 256 Insulin-like growth factor-binding protein 7

As used herein, the term “C—X—C motif chemokine 6” refers to one or more polypeptides present in a biological sample that are derived from the C—X—C motif chemokine 6 precursor (human precursor: Swiss-Prot P80162 (SEQ ID NO: 3))

        10         20         30         40         50         60 MSLPSSRAAR VPGPSGSLCA LLALLLLLTP PGPLASAGPV SAVLTELRCT CLRVTLRVNP         70         80         90        100        110 KTIGKLQVFP AGPQCSKVEV VASLKNGKQV CLDPEAPFLK KVIQKILDSG NKKN

The following domains have been identified in C—X—C motif chemokine 6:

Residues Length Domain ID 1-37 37 Signal peptide 38-114 77 C-X-C motif chemokine 6 40-114 75 C-X-C motif chemokine 6 (N-processed variant 1) 43-114 72 C-X-C motif chemokine 6 (N-processed variant 2) 46-114 69 C-X-C motif chemokine 6 (N-processed variant 3)

As used herein, the term “C—C motif chemokine 13” refers to one or more polypeptides present in a biological sample that are derived from the C—C motif chemokine 13 precursor (human precursor: Swiss-Prot Q99616 (SEQ ID NO: 4))

        10         20         30         40         50         60 MKVSAVLLCL LLMTAAFNPQ GLAQPDALNV PSTCCFTFSS KKISLQRLKS YVITTSRCPQ         70         80         90 KAVIFRTKLG KEICADPKEK WVQNYMKHLG RKAHTLKT

The following domains have been identified in C—C motif chemokine 13:

Residues Length Domain ID  1-16 16 Signal peptide 17-98 82 C-C motif chemokine 13, long chain 22-98 82 C-C motif chemokine 13, medium chain 24-98 82 C-C motif chemokine 13, short chain

As used herein, the term “relating a signal to the presence or amount” of an analyte reflects the following understanding. Assay signals are typically related to the presence or amount of an analyte through the use of a standard curve calculated using known concentrations of the analyte of interest. As the term is used herein, an assay is “configured to detect” an analyte if an assay can generate a detectable signal indicative of the presence or amount of a physiologically relevant concentration of the analyte. Because an antibody epitope is on the order of 8 amino acids, an immunoassay configured to detect a marker of interest will also detect polypeptides related to the marker sequence, so long as those polypeptides contain the epitope(s) necessary to bind to the antibody or antibodies used in the assay. The term “related marker” as used herein with regard to a biomarker such as one of the kidney injury markers described herein refers to one or more fragments, variants, etc., of a particular marker or its biosynthetic parent that may be detected as a surrogate for the marker itself or as independent biomarkers. The term also refers to one or more polypeptides present in a biological sample that are derived from the biomarker precursor complexed to additional species, such as binding proteins, receptors, heparin, lipids, sugars, etc.

In this regard, the skilled artisan will understand that the signals obtained from an immunoassay are a direct result of complexes formed between one or more antibodies and the target biomolecule (i.e., the analyte) and polypeptides containing the necessary epitope(s) to which the antibodies bind. While such assays may detect the full length biomarker and the assay result be expressed as a concentration of a biomarker of interest, the signal from the assay is actually a result of all such “immunoreactive” polypeptides present in the sample. Expression of biomarkers may also be determined by means other than immunoassays, including protein measurements (such as dot blots, western blots, chromatographic methods, mass spectrometry, etc.) and nucleic acid measurements (mRNA quatitation). This list is not meant to be limiting.

The term “positive going” marker as that term is used herein refer to a marker that is determined to be elevated in subjects suffering from a disease or condition, relative to subjects not suffering from that disease or condition. The term “negative going” marker as that term is used herein refer to a marker that is determined to be reduced in subjects suffering from a disease or condition, relative to subjects not suffering from that disease or condition.

The term “subject” as used herein refers to a human or non-human organism. Thus, the methods and compositions described herein are applicable to both human and veterinary disease. Further, while a subject is preferably a living organism, the invention described herein may be used in post-mortem analysis as well. Preferred subjects are humans, and most preferably “patients,” which as used herein refers to living humans that are receiving medical care for a disease or condition. This includes persons with no defined illness who are being investigated for signs of pathology.

Preferably, an analyte is measured in a sample. Such a sample may be obtained from a subject, or may be obtained from biological materials intended to be provided to the subject. For example, a sample may be obtained from a kidney being evaluated for possible transplantation into a subject, and an analyte measurement used to evaluate the kidney for preexisting damage. Preferred samples are body fluid samples.

The term “body fluid sample” as used herein refers to a sample of bodily fluid obtained for the purpose of diagnosis, prognosis, classification or evaluation of a subject of interest, such as a patient or transplant donor. In certain embodiments, such a sample may be obtained for the purpose of determining the outcome of an ongoing condition or the effect of a treatment regimen on a condition. Preferred body fluid samples include blood, serum, plasma, cerebrospinal fluid, urine, saliva, sputum, and pleural effusions. In addition, one of skill in the art would realize that certain body fluid samples would be more readily analyzed following a fractionation or purification procedure, for example, separation of whole blood into serum or plasma components.

The term “diagnosis” as used herein refers to methods by which the skilled artisan can estimate and/or determine the probability (“a likelihood”) of whether or not a patient is suffering from a given disease or condition. In the case of the present invention, “diagnosis” includes using the results of an assay, most preferably an immunoassay, for a kidney injury marker of the present invention, optionally together with other clinical characteristics, to arrive at a diagnosis (that is, the occurrence or nonoccurrence) of an acute renal injury or ARF for the subject from which a sample was obtained and assayed. That such a diagnosis is “determined” is not meant to imply that the diagnosis is 100% accurate. Many biomarkers are indicative of multiple conditions. The skilled clinician does not use biomarker results in an informational vacuum, but rather test results are used together with other clinical indicia to arrive at a diagnosis. Thus, a measured biomarker level on one side of a predetermined diagnostic threshold indicates a greater likelihood of the occurrence of disease in the subject relative to a measured level on the other side of the predetermined diagnostic threshold.

Similarly, a prognostic risk signals a probability (“a likelihood”) that a given course or outcome will occur. A level or a change in level of a prognostic indicator, which in turn is associated with an increased probability of morbidity (e.g., worsening renal function, future ARF, or death) is referred to as being “indicative of an increased likelihood” of an adverse outcome in a patient.

Marker Assays

In general, immunoassays involve contacting a sample containing or suspected of containing a biomarker of interest with at least one antibody that specifically binds to the biomarker. A signal is then generated indicative of the presence or amount of complexes formed by the binding of polypeptides in the sample to the antibody. The signal is then related to the presence or amount of the biomarker in the sample. Numerous methods and devices are well known to the skilled artisan for the detection and analysis of biomarkers. See, e.g., U.S. Pat. Nos. 6,143,576; 6,113,855; 6,019,944; 5,985,579; 5,947,124; 5,939,272; 5,922,615; 5,885,527; 5,851,776; 5,824,799; 5,679,526; 5,525,524; and 5,480,792, and The Immunoassay Handbook, David Wild, ed. Stockton Press, New York, 1994, each of which is hereby incorporated by reference in its entirety, including all tables, figures and claims.

The assay devices and methods known in the art can utilize labeled molecules in various sandwich, competitive, or non-competitive assay formats, to generate a signal that is related to the presence or amount of the biomarker of interest. Suitable assay formats also include chromatographic, mass spectrographic, and protein “blotting” methods. Additionally, certain methods and devices, such as biosensors and optical immunoassays, may be employed to determine the presence or amount of analytes without the need for a labeled molecule. See, e.g., U.S. Pat. Nos. 5,631,171; and 5,955,377, each of which is hereby incorporated by reference in its entirety, including all tables, figures and claims. One skilled in the art also recognizes that robotic instrumentation including but not limited to Beckman ACCESS®, Abbott AXSYM®, Roche ELECSYS®, Dade Behring STRATUS® systems are among the immunoassay analyzers that are capable of performing immunoassays. But any suitable immunoassay may be utilized, for example, enzyme-linked immunoassays (ELISA), radioimmunoassays (RIAs), competitive binding assays, and the like.

Antibodies or other polypeptides may be immobilized onto a variety of solid supports for use in assays. Solid phases that may be used to immobilize specific binding members include those developed and/or used as solid phases in solid phase binding assays. Examples of suitable solid phases include membrane filters, cellulose-based papers, beads (including polymeric, latex and paramagnetic particles), glass, silicon wafers, microparticles, nanoparticles, TentaGels, AgroGels, PEGA gels, SPOCC gels, and multiple-well plates. An assay strip could be prepared by coating the antibody or a plurality of antibodies in an array on solid support. This strip could then be dipped into the test sample and then processed quickly through washes and detection steps to generate a measurable signal, such as a colored spot. Antibodies or other polypeptides may be bound to specific zones of assay devices either by conjugating directly to an assay device surface, or by indirect binding. In an example of the later case, antibodies or other polypeptides may be immobilized on particles or other solid supports, and that solid support immobilized to the device surface.

Biological assays require methods for detection, and one of the most common methods for quantitation of results is to conjugate a detectable label to a protein or nucleic acid that has affinity for one of the components in the biological system being studied. Detectable labels may include molecules that are themselves detectable (e.g., fluorescent moieties, electrochemical labels, metal chelates, etc.) as well as molecules that may be indirectly detected by production of a detectable reaction product (e.g., enzymes such as horseradish peroxidase, alkaline phosphatase, etc.) or by a specific binding molecule which itself may be detectable (e.g., biotin, digoxigenin, maltose, oligohistidine, 2,4-dintrobenzene, phenylarsenate, ssDNA, dsDNA, etc.).

Preparation of solid phases and detectable label conjugates often comprise the use of chemical cross-linkers. Cross-linking reagents contain at least two reactive groups, and are divided generally into homofunctional cross-linkers (containing identical reactive groups) and heterofunctional cross-linkers (containing non-identical reactive groups). Homobifunctional cross-linkers that couple through amines, sulfhydryls or react non-specifically are available from many commercial sources. Maleimides, alkyl and aryl halides, alpha-haloacyls and pyridyl disulfides are thiol reactive groups. Maleimides, alkyl and aryl halides, and alpha-haloacyls react with sulfhydryls to form thiol ether bonds, while pyridyl disulfides react with sulfhydryls to produce mixed disulfides. The pyridyl disulfide product is cleavable. Imidoesters are also very useful for protein-protein cross-links. A variety of heterobifunctional cross-linkers, each combining different attributes for successful conjugation, are commercially available.

In certain aspects, the present invention provides kits for the analysis of the described kidney injury markers. The kit comprises reagents for the analysis of at least one test sample which comprise at least one antibody that a kidney injury marker. The kit can also include devices and instructions for performing one or more of the diagnostic and/or prognostic correlations described herein. Preferred kits will comprise an antibody pair for performing a sandwich assay, or a labeled species for performing a competitive assay, for the analyte. Preferably, an antibody pair comprises a first antibody conjugated to a solid phase and a second antibody conjugated to a detectable label, wherein each of the first and second antibodies that bind a kidney injury marker. Most preferably each of the antibodies are monoclonal antibodies. The instructions for use of the kit and performing the correlations can be in the form of labeling, which refers to any written or recorded material that is attached to, or otherwise accompanies a kit at any time during its manufacture, transport, sale or use. For example, the term labeling encompasses advertising leaflets and brochures, packaging materials, instructions, audio or video cassettes, computer discs, as well as writing imprinted directly on kits.

Antibodies

The term “antibody” as used herein refers to a peptide or polypeptide derived from, modeled after or substantially encoded by an immunoglobulin gene or immunoglobulin genes, or fragments thereof, capable of specifically binding an antigen or epitope. See, e.g. Fundamental Immunology, 3rd Edition, W. E. Paul, ed., Raven Press, N.Y. (1993); Wilson (1994; J. Immunol. Methods 175:267-273; Yarmush (1992) J. Biochem. Biophys. Methods 25:85-97. The term antibody includes antigen-binding portions, i.e., “antigen binding sites,” (e.g., fragments, subsequences, complementarity determining regions (CDRs)) that retain capacity to bind antigen, including (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL and CH1 domains; (ii) a F(ab′)2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting of the VH and CH1 domains; (iv) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody, (v) a dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of a VH domain; and (vi) an isolated complementarity determining region (CDR). Single chain antibodies are also included by reference in the term “antibody.”

Antibodies used in the immunoassays described herein preferably specifically bind to a kidney injury marker of the present invention. The term “specifically binds” is not intended to indicate that an antibody binds exclusively to its intended target since, as noted above, an antibody binds to any polypeptide displaying the epitope(s) to which the antibody binds. Rather, an antibody “specifically binds” if its affinity for its intended target is about 5-fold greater when compared to its affinity for a non-target molecule which does not display the appropriate epitope(s). Preferably the affinity of the antibody will be at least about 5 fold, preferably 10 fold, more preferably 25-fold, even more preferably 50-fold, and most preferably 100-fold or more, greater for a target molecule than its affinity for a non-target molecule. In preferred embodiments, Preferred antibodies bind with affinities of at least about 10⁷ M⁻¹, and preferably between about 10⁸ M⁻¹ to about 10⁹ M⁻¹, about 10⁹ M⁻¹ to about 10¹⁰ M⁻¹, or about 10¹⁰ m⁻¹ to about 10¹² M⁻¹.

Affinity is calculated as K_(d)=k_(off)/k_(on) (k_(off) is the dissociation rate constant, K_(on) is the association rate constant and K_(d) is the equilibrium constant). Affinity can be determined at equilibrium by measuring the fraction bound (r) of labeled ligand at various concentrations (c). The data are graphed using the Scatchard equation: r/c=K(n−r): where r=moles of bound ligand/mole of receptor at equilibrium; c=free ligand concentration at equilibrium; K=equilibrium association constant; and n=number of ligand binding sites per receptor molecule. By graphical analysis, r/c is plotted on the Y-axis versus r on the X-axis, thus producing a Scatchard plot. Antibody affinity measurement by Scatchard analysis is well known in the art. See, e.g., van Erp et al., J. Immunoassay 12: 425-43, 1991; Nelson and Griswold, Comput. Methods Programs Biomed. 27: 65-8, 1988.

The term “epitope” refers to an antigenic determinant capable of specific binding to an antibody. Epitopes usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and usually have specific three dimensional structural characteristics, as well as specific charge characteristics. Conformational and nonconformational epitopes are distinguished in that the binding to the former but not the latter is lost in the presence of denaturing solvents.

Numerous publications discuss the use of phage display technology to produce and screen libraries of polypeptides for binding to a selected analyte. See, e.g, Cwirla et al., Proc. Natl. Acad. Sci. USA 87, 6378-82, 1990; Devlin et al., Science 249, 404-6, 1990, Scott and Smith, Science 249, 386-88, 1990; and Ladner et al., U.S. Pat. No. 5,571,698. A basic concept of phage display methods is the establishment of a physical association between DNA encoding a polypeptide to be screened and the polypeptide. This physical association is provided by the phage particle, which displays a polypeptide as part of a capsid enclosing the phage genome which encodes the polypeptide. The establishment of a physical association between polypeptides and their genetic material allows simultaneous mass screening of very large numbers of phage bearing different polypeptides. Phage displaying a polypeptide with affinity to a target bind to the target and these phage are enriched by affinity screening to the target. The identity of polypeptides displayed from these phage can be determined from their respective genomes. Using these methods a polypeptide identified as having a binding affinity for a desired target can then be synthesized in bulk by conventional means. See, e.g., U.S. Pat. No. 6,057,098, which is hereby incorporated in its entirety, including all tables, figures, and claims.

The antibodies that are generated by these methods may then be selected by first screening for affinity and specificity with the purified polypeptide of interest and, if required, comparing the results to the affinity and specificity of the antibodies with polypeptides that are desired to be excluded from binding. The screening procedure can involve immobilization of the purified polypeptides in separate wells of microtiter plates. The solution containing a potential antibody or groups of antibodies is then placed into the respective microtiter wells and incubated for about 30 min to 2 h. The microtiter wells are then washed and a labeled secondary antibody (for example, an anti-mouse antibody conjugated to alkaline phosphatase if the raised antibodies are mouse antibodies) is added to the wells and incubated for about 30 min and then washed. Substrate is added to the wells and a color reaction will appear where antibody to the immobilized polypeptide(s) are present.

The antibodies so identified may then be further analyzed for affinity and specificity in the assay design selected. In the development of immunoassays for a target protein, the purified target protein acts as a standard with which to judge the sensitivity and specificity of the immunoassay using the antibodies that have been selected. Because the binding affinity of various antibodies may differ; certain antibody pairs (e.g., in sandwich assays) may interfere with one another sterically, etc., assay performance of an antibody may be a more important measure than absolute affinity and specificity of an antibody.

While the present application describes antibody-based binding assays in detail, alternatives to antibodies as binding species in assays are well known in the art. These include receptors for a particular target, aptamers, etc. Aptamers are oligonucleic acid or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist. High-affinity aptamers containing modified nucleotides conferring improved characteristics on the ligand, such as improved in vivo stability or improved delivery characteristics. Examples of such modifications include chemical substitutions at the ribose and/or phosphate and/or base positions, and may include amino acid side chain functionalities.

Assay Correlations

The term “correlating” as used herein in reference to the use of biomarkers refers to comparing the presence or amount of the biomarker(s) in a patient to its presence or amount in persons known to suffer from, or known to be at risk of, a given condition; or in persons known to be free of a given condition. Often, this takes the form of comparing an assay result in the form of a biomarker concentration to a predetermined threshold selected to be indicative of the occurrence or nonoccurrence of a disease or the likelihood of some future outcome.

Selecting a diagnostic threshold involves, among other things, consideration of the probability of disease, distribution of true and false diagnoses at different test thresholds, and estimates of the consequences of treatment (or a failure to treat) based on the diagnosis. For example, when considering administering a specific therapy which is highly efficacious and has a low level of risk, few tests are needed because clinicians can accept substantial diagnostic uncertainty. On the other hand, in situations where treatment options are less effective and more risky, clinicians often need a higher degree of diagnostic certainty. Thus, cost/benefit analysis is involved in selecting a diagnostic threshold.

Suitable thresholds may be determined in a variety of ways. For example, one recommended diagnostic threshold for the diagnosis of acute myocardial infarction using cardiac troponin is the 97.5th percentile of the concentration seen in a normal population. Another method may be to look at serial samples from the same patient, where a prior “baseline” result is used to monitor for temporal changes in a biomarker level.

Population studies may also be used to select a decision threshold. Reciever Operating Characteristic (“ROC”) arose from the field of signal dectection therory developed during World War II for the analysis of radar images, and ROC analysis is often used to select a threshold able to best distinguish a “diseased” subpopulation from a “nondiseased” subpopulation. A false positive in this case occurs when the person tests positive, but actually does not have the disease. A false negative, on the other hand, occurs when the person tests negative, suggesting they are healthy, when they actually do have the disease. To draw a ROC curve, the true positive rate (TPR) and false positive rate (FPR) are determined as the decision threshold is varied continuously. Since TPR is equivalent with sensitivity and FPR is equal to 1-specificity, the ROC graph is sometimes called the sensitivity vs (1-specificity) plot. A perfect test will have an area under the ROC curve of 1.0; a random test will have an area of 0.5. A threshold is selected to provide an acceptable level of specificity and sensitivity.

In this context, “diseased” is meant to refer to a population having one characteristic (the presence of a disease or condition or the occurrence of some outcome) and “nondiseased” is meant to refer to a population lacking the characteristic. While a single decision threshold is the simplest application of such a method, multiple decision thresholds may be used. For example, below a first threshold, the absence of disease may be assigned with relatively high confidence, and above a second threshold the presence of disease may also be assigned with relatively high confidence. Between the two thresholds may be considered indeterminate. This is meant to be exemplary in nature only.

In addition to threshold comparisons, other methods for correlating assay results to a patient classification (occurrence or nonoccurrence of disease, likelihood of an outcome, etc.) include decision trees, rule sets, Bayesian methods, and neural network methods. These methods can produce probability values representing the degree to which a subject belongs to one classification out of a plurality of classifications.

Measures of test accuracy may be obtained as described in Fischer et al., Intensive Care Med. 29: 1043-51, 2003, and used to determine the effectiveness of a given biomarker. These measures include sensitivity and specificity, predictive values, likelihood ratios, diagnostic odds ratios, and ROC curve areas. The area under the curve (“AUC”) of a ROC plot is equal to the probability that a classifier will rank a randomly chosen positive instance higher than a randomly chosen negative one. The area under the ROC curve may be thought of as equivalent to the Mann-Whitney U test, which tests for the median difference between scores obtained in the two groups considered if the groups are of continuous data, or to the Wilcoxon test of ranks.

As discussed above, suitable tests may exhibit one or more of the following results on these various measures: a specificity of greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9 and most preferably at least 0.95, with a corresponding sensitivity greater than 0.2, preferably greater than 0.3, more preferably greater than 0.4, still more preferably at least 0.5, even more preferably 0.6, yet more preferably greater than 0.7, still more preferably greater than 0.8, more preferably greater than 0.9, and most preferably greater than 0.95; a sensitivity of greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9 and most preferably at least 0.95, with a corresponding specificity greater than 0.2, preferably greater than 0.3, more preferably greater than 0.4, still more preferably at least 0.5, even more preferably 0.6, yet more preferably greater than 0.7, still more preferably greater than 0.8, more preferably greater than 0.9, and most preferably greater than 0.95; at least 75% sensitivity, combined with at least 75% specificity; a ROC curve area of greater than 0.5, preferably at least 0.6, more preferably 0.7, still more preferably at least 0.8, even more preferably at least 0.9, and most preferably at least 0.95; an odds ratio different from 1, preferably at least about 2 or more or about 0.5 or less, more preferably at least about 3 or more or about 0.33 or less, still more preferably at least about 4 or more or about 0.25 or less, even more preferably at least about 5 or more or about 0.2 or less, and most preferably at least about 10 or more or about 0.1 or less; a positive likelihood ratio (calculated as sensitivity/(1-specificity)) of greater than 1, at least 2, more preferably at least 3, still more preferably at least 5, and most preferably at least 10; and or a negative likelihood ratio (calculated as (1-sensitivity)/specificity) of less than 1, less than or equal to 0.5, more preferably less than or equal to 0.3, and most preferably less than or equal to 0.1

Additional clinical indicia may be combined with the kidney injury marker assay result(s) of the present invention. These include other biomarkers related to renal status. Examples include the following, which recite the common biomarker name, followed by the Swiss-Prot entry number for that biomarker or its parent: Actin (P68133); Adenosine deaminase binding protein (DPP4, P27487); Alpha-1-acid glycoprotein 1 (P02763); Alpha-1-microglobulin (P02760); Albumin (P02768); Angiotensinogenase (Renin, P00797); Annexin A2 (P07355); Beta-glucuronidase (P08236); B-2-microglobulin (P61679); Beta-galactosidase (P16278); BMP-7 (P18075); Brain natriuretic peptide (proBNP, BNP-32, NTproBNP; P16860); Calcium-binding protein Beta (S100-beta, P04271); Carbonic anhydrase (Q16790); Casein Kinase 2 (P68400); Ceruloplasmin (P00450); Clusterin (P10909); Complement C3 (P01024); Cysteine-rich protein (CYR61, O00622); Cytochrome C(P99999); Epidermal growth factor (EGF, P01133); Endothelin-1 (P05305); Exosomal Fetuin-A (P02765); Fatty acid-binding protein, heart (FABP3, P05413); Fatty acid-binding protein, liver (P07148); Ferritin (light chain, P02793; heavy chain P02794); Fructose-1,6-biphosphatase (P09467); GRO-alpha (CXCL1, (P09341); Growth Hormone (P01241); Hepatocyte growth factor (P14210); Insulin-like growth factor I (P01343); Immunoglobulin G; Immunoglobulin Light Chains (Kappa and Lambda); Interferon gamma (P01308); Lysozyme (P61626); Interleukin-1alpha (P01583); Interleukin-2 (P60568); Interleukin-4 (P60568); Interleukin-9 (P15248); Interleukin-12p40 (P29460); Interleukin-13 (P35225); Interleukin-16 (Q14005); L1 cell adhesion molecule (P32004); Lactate dehydrogenase (P00338); Leucine Aminopeptidase (P28838); Meprin A-alpha subunit (Q16819); Meprin A-beta subunit (Q16820); Midkine (P21741); MIP2-alpha (CXCL2, P19875); MMP-2 (P08253); MMP-9 (P14780); Netrin-1 (O95631); Neutral endopeptidase (P08473); Osteopontin (P10451); Renal papillary antigen 1 (RPA1); Renal papillary antigen 2 (RPA2); Retinol binding protein (P09455); Ribonuclease; S100 calcium-binding protein A6 (P06703); Serum Amyloid P Component (P02743); Sodium/Hydrogen exchanger isoform (NHE3, P48764); Spermidine/spermine N1-acetyltransferase (P21673); TGF-Beta1 (P01137); Transferrin (P02787); Trefoil factor 3 (TFF3, Q07654); Toll-Like protein 4 (O00206); Total protein; Tubulointerstitial nephritis antigen (Q9UJW2); Uromodulin (Tamm-Horsfall protein, P07911).

For purposes of risk stratification, Adiponectin (Q15848); Alkaline phosphatase (P05186); Aminopeptidase N(P15144); CalbindinD28k (P05937); Cystatin C(P01034); 8 subunit of FIFO ATPase (P03928); Gamma-glutamyltransferase (P19440); GSTa (alpha-glutathione-S-transferase, P08263); GSTpi (Glutathione-S-transferase P; GST class-pi; P09211); IGFBP-1 (P08833); IGFBP-2 (P18065); IGFBP-6 (P24592); Integral membrane protein 1 (Itml, P46977); Interleukin-6 (P05231); Interleukin-8 (P10145); Interleukin-18 (Q14116); IP-10 (10 kDa interferon-gamma-induced protein, P02778); IRPR (IFRD1, O00458); Isovaleryl-CoA dehydrogenase (IVD, P26440); I-TAC/CXCL11 (O14625); Keratin 19 (P08727); Kim-1 (Hepatitis A virus cellular receptor 1, O43656); L-arginine:glycine amidinotransferase (P50440); Leptin (P41159); Lipocalin2 (NGAL, P80188); MCP-1 (P13500); MIG (Gamma-interferon-induced monokine Q07325); MIP-1a (P10147); MIP-3a (P78556); MIP-1beta (P13236); MIP-1d (Q16663); NAG (N-acetyl-beta-D-glucosaminidase, P54802); Organic ion transporter (OCT2, O15244); Osteoprotegerin (O14788); P8 protein (O60356); Plasminogen activator inhibitor 1 (PAI-1, P05121); ProANP(1-98) (P01160); Protein phosphatase 1-beta (PPI-beta, P62140); Rab GDI-beta (P50395); Renal kallikrein (Q86U61); RT1.B-1 (alpha) chain of the integral membrane protein (Q5Y7A8); Soluble tumor necrosis factor receptor superfamily member 1A (sTNFR-I, P19438); Soluble tumor necrosis factor receptor superfamily member 1B (sTNFR-II, P20333); Tissue inhibitor of metalloproteinases 3 (TIMP-3, P35625); uPAR (Q03405) may be combined with the kidney injury marker assay result(s) of the present invention.

Other clinical indicia which may be combined with the kidney injury marker assay result(s) of the present invention includes demographic information (e.g., weight, sex, age, race), medical history (e.g., family history, type of surgery, pre-existing disease such as aneurism, congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, or sepsis, type of toxin exposure such as NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin), clinical variables (e.g., blood pressure, temperature, respiration rate), risk scores (APACHE score, PREDICT score, TIMI Risk Score for UA/NSTEMI, Framingham Risk Score), a urine total protein measurement, a glomerular filtration rate, an estimated glomerular filtration rate, a urine production rate, a serum or plasma creatinine concentration, a renal papillary antigen 1 (RPA1) measurement; a renal papillary antigen 2 (RPA2) measurement; a urine creatinine concentration, a fractional excretion of sodium, a urine sodium concentration, a urine creatinine to serum or plasma creatinine ratio, a urine specific gravity, a urine osmolality, a urine urea nitrogen to plasma urea nitrogen ratio, a plasma BUN to creatnine ratio, and/or a renal failure index calculated as urine sodium/(urine creatinine/plasma creatinine). Other measures of renal function which may be combined with the kidney injury marker assay result(s) are described hereinafter and in Harrison's Principles of Internal Medicine, 17^(th) Ed., McGraw Hill, New York, pages 1741-1830, and Current Medical Diagnosis & Treatment 2008, 47^(th) Ed, McGraw Hill, New York, pages 785-815, each of which are hereby incorporated by reference in their entirety.

Combining assay results/clinical indicia in this manner can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, etc. This list is not meant to be limiting.

Diagnosis of Acute Renal Failure

As noted above, the terms “acute renal (or kidney) injury” and “acute renal (or kidney) failure” as used herein are defined in part in terms of changes in serum creatinine from a baseline value. Most definitions of ARF have common elements, including the use of serum creatinine and, often, urine output. Patients may present with renal dysfunction without an available baseline measure of renal function for use in this comparison. In such an event, one may estimate a baseline serum creatinine value by assuming the patient initially had a normal GFR. Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. Glomerular filtration rate (GFR) can be calculated by measuring any chemical that has a steady level in the blood, and is freely filtered but neither reabsorbed nor secreted by the kidneys. GFR is typically expressed in units of ml/min:

${G\; F\; R} = \frac{{Urine}\mspace{14mu} {Concentration} \times {Urine}\mspace{14mu} {Flow}}{{Plasma}\mspace{14mu} {Concentration}}$

By normalizing the GFR to the body surface area, a GFR of approximately 75-100 ml/min per 1.73 m² can be assumed. The rate therefore measured is the quantity of the substance in the urine that originated from a calculable volume of blood.

There are several different techniques used to calculate or estimate the glomerular filtration rate (GFR or eGFR). In clinical practice, however, creatinine clearance is used to measure GFR. Creatinine is produced naturally by the body (creatinine is a metabolite of creatine, which is found in muscle). It is freely filtered by the glomerulus, but also actively secreted by the renal tubules in very small amounts such that creatinine clearance overestimates actual GFR by 10-20%. This margin of error is acceptable considering the ease with which creatinine clearance is measured.

Creatinine clearance (CCr) can be calculated if values for creatinine's urine concentration (U_(Cr)), urine flow rate (V), and creatinine's plasma concentration (P_(Cr)) are known. Since the product of urine concentration and urine flow rate yields creatinine's excretion rate, creatinine clearance is also said to be its excretion rate (I_(Cr)×V) divided by its plasma concentration. This is commonly represented mathematically as:

$C_{Cr} = \frac{U_{Cr} - V}{P_{Cr}}$

Commonly a 24 hour urine collection is undertaken, from empty-bladder one morning to the contents of the bladder the following morning, with a comparative blood test then taken:

$C_{Cr} = \frac{U_{Cr} \times 24\text{-}{hour}\mspace{14mu} {volume}}{P_{Cr} \times 24 \times 60\mspace{14mu} {mins}}$

To allow comparison of results between people of different sizes, the CCr is often corrected for the body surface area (BSA) and expressed compared to the average sized man as ml/min/1.73 m2. While most adults have a BSA that approaches 1.7 (1.6-1.9), extremely obese or slim patients should have their CCr corrected for their actual BSA:

$C_{{Cr} - {corrected}} = \frac{C_{Cr} \times 1.73`}{B\; S\; A}$

The accuracy of a creatinine clearance measurement (even when collection is complete) is limited because as glomerular filtration rate (GFR) falls creatinine secretion is increased, and thus the rise in serum creatinine is less. Thus, creatinine excretion is much greater than the filtered load, resulting in a potentially large overestimation of the GFR (as much as a twofold difference). However, for clinical purposes it is important to determine whether renal function is stable or getting worse or better. This is often determined by monitoring serum creatinine alone. Like creatinine clearance, the serum creatinine will not be an accurate reflection of GFR in the non-steady-state condition of ARF. Nonetheless, the degree to which serum creatinine changes from baseline will reflect the change in GFR. Serum creatinine is readily and easily measured and it is specific for renal function.

For purposes of determining urine output on a Urine output on a mL/kg/hr basis, hourly urine collection and measurement is adequate. In the case where, for example, only a cumulative 24-h output was available and no patient weights are provided, minor modifications of the RIFLE urine output criteria have been described. For example, Bagshaw et al., Nephrol. Dial. Transplant. 23: 1203-1210, 2008, assumes an average patient weight of 70 kg, and patients are assigned a RIFLE classification based on the following: <35 mL/h (Risk), <21 mL/h (Injury) or <4 mL/h (Failure).

Selecting a Treatment Regimen

Once a diagnosis is obtained, the clinician can readily select a treatment regimen that is compatible with the diagnosis, such as initiating renal replacement therapy, withdrawing delivery of compounds that are known to be damaging to the kidney, kidney transplantation, delaying or avoiding procedures that are known to be damaging to the kidney, modifying diuretic administration, initiating goal directed therapy, etc. The skilled artisan is aware of appropriate treatments for numerous diseases discussed in relation to the methods of diagnosis described herein. See, e.g., Merck Manual of Diagnosis and Therapy, 17th Ed. Merck Research Laboratories, Whitehouse Station, N.J., 1999. In addition, since the methods and compositions described herein provide prognostic information, the markers of the present invention may be used to monitor a course of treatment. For example, improved or worsened prognostic state may indicate that a particular treatment is or is not efficacious.

One skilled in the art readily appreciates that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The examples provided herein are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.

Example 1 Contrast-Induced Nephropathy Sample Collection

The objective of this sample collection study is to collect samples of plasma and urine and clinical data from patients before and after receiving intravascular contrast media. Approximately 250 adults undergoing radiographic/angiographic procedures involving intravascular administration of iodinated contrast media are enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older; undergoing a radiographic/angiographic procedure (such as a CT scan or coronary intervention) involving the intravascular administration of contrast media; expected to be hospitalized for at least 48 hours after contrast administration. able and willing to provide written informed consent for study participation and to comply with all study procedures.

Exclusion Criteria

renal transplant recipients; acutely worsening renal function prior to the contrast procedure; already receiving dialysis (either acute or chronic) or in imminent need of dialysis at enrollment; expected to undergo a major surgical procedure (such as involving cardiopulmonary bypass) or an additional imaging procedure with contrast media with significant risk for further renal insult within the 48 hrs following contrast administration; participation in an interventional clinical study with an experimental therapy within the previous 30 days; known infection with human immunodeficiency virus (HIV) or a hepatitis virus.

Immediately prior to the first contrast administration (and after any pre-procedure hydration), an EDTA anti-coagulated blood sample (10 mL) and a urine sample (10 mL) are collected from each patient. Blood and urine samples are then collected at 4 (±0.5), 8 (±1), 24 (±2) 48 (±2), and 72 (±2) hrs following the last administration of contrast media during the index contrast procedure. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are processed to plasma at the clinical site, frozen and shipped to Astute Medical, Inc., San Diego, Calif. The study urine samples are frozen and shipped to Astute Medical, Inc.

Serum creatinine is assessed at the site immediately prior to the first contrast administration (after any pre-procedure hydration) and at 4 (±0.5), 8 (±1), 24 (±2) and 48 (±2)), and 72 (±2) hours following the last administration of contrast (ideally at the same time as the study samples are obtained). In addition, each patient's status is evaluated through day 30 with regard to additional serum and urine creatinine measurements, a need for dialysis, hospitalization status, and adverse clinical outcomes (including mortality).

Prior to contrast administration, each patient is assigned a risk based on the following assessment: systolic blood pressure <80 mm Hg=5 points; intra-arterial balloon pump=5 points; congestive heart failure (Class III-IV or history of pulmonary edema)=5 points; age >75 yrs=4 points; hematocrit level <39% for men, <35% for women=3 points; diabetes=3 points; contrast media volume=1 point for each 100 mL; serum creatinine level >1.5 g/dL=4 points OR estimated GFR 40-60 mL/min/1.73 m²=2 points, 20-40 mL/min/1.73 m²=4 points, <20 mL/min/1.73 m²=6 points. The risks assigned are as follows: risk for CIN and dialysis: 5 or less total points=risk of CIN-7.5%, risk of dialysis-0.04%; 6-10 total points=risk of CIN-14%, risk of dialysis-0.12%; 11-16 total points=risk of CIN-26.1%, risk of dialysis-1.09%; >16 total points=risk of CIN-57.3%, risk of dialysis-12.8%.

Example 2 Cardiac Surgery Sample Collection

The objective of this sample collection study is to collect samples of plasma and urine and clinical data from patients before and after undergoing cardiovascular surgery, a procedure known to be potentially damaging to kidney function. Approximately 900 adults undergoing such surgery are enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older; undergoing cardiovascular surgery; Toronto/Ottawa Predictive Risk Index for Renal Replacement risk score of at least 2 (Wijeysundera et al., JAMA 297: 1801-9, 2007); and able and willing to provide written informed consent for study participation and to comply with all study procedures.

Exclusion Criteria

known pregnancy; previous renal transplantation; acutely worsening renal function prior to enrollment (e.g., any category of RIFLE criteria); already receiving dialysis (either acute or chronic) or in imminent need of dialysis at enrollment; currently enrolled in another clinical study or expected to be enrolled in another clinical study within 7 days of cardiac surgery that involves drug infusion or a therapeutic intervention for AKI; known infection with human immunodeficiency virus (HIV) or a hepatitis virus.

Within 3 hours prior to the first incision (and after any pre-procedure hydration), an EDTA anti-coagulated blood sample (10 mL), whole blood (3 mL), and a urine sample (35 mL) are collected from each patient. Blood and urine samples are then collected at 3 (±0.5), 6 (±0.5), 12 (±1), 24 (±2) and 48 (±2) hrs following the procedure and then daily on days 3 through 7 if the subject remains in the hospital. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are frozen and shipped to Astute Medical, Inc., San Diego, Calif. The study urine samples are frozen and shipped to Astute Medical, Inc.

Example 3 Acutely Ill Subject Sample Collection

The objective of this study is to collect samples from acutely ill patients. Approximately 900 adults expected to be in the ICU for at least 48 hours will be enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older; Study population 1: approximately 300 patients that have at least one of: shock (SBP <90 mmHg and/or need for vasopressor support to maintain MAP >60 mmHg and/or documented drop in SBP of at least 40 mmHg); and sepsis; Study population 2: approximately 300 patients that have at least one of: IV antibiotics ordered in computerized physician order entry (CPOE) within 24 hours of enrollment; contrast media exposure within 24 hours of enrollment; increased Intra-Abdominal Pressure with acute decompensated heart failure; and severe trauma as the primary reason for ICU admission and likely to be hospitalized in the ICU for 48 hours after enrollment; Study population 3: approximately 300 patients expected to be hospitalized through acute care setting (ICU or ED) with a known risk factor for acute renal injury (e.g. sepsis, hypotension/shock (Shock=systolic BP<90 mmHg and/or the need for vasopressor support to maintain a MAP >60 mmHg and/or a documented drop in SBP >40 mmHg), major trauma, hemorrhage, or major surgery); and/or expected to be hospitalized to the ICU for at least 24 hours after enrollment.

Exclusion Criteria

known pregnancy; institutionalized individuals; previous renal transplantation; known acutely worsening renal function prior to enrollment (e.g., any category of RIFLE criteria); received dialysis (either acute or chronic) within 5 days prior to enrollment or in imminent need of dialysis at the time of enrollment; known infection with human immunodeficiency virus (HIV) or a hepatitis virus; meets only the SBP <90 mmHg inclusion criterion set forth above, and does not have shock in the attending physician's or principal investigator's opinion.

After providing informed consent, an EDTA anti-coagulated blood sample (10 mL) and a urine sample (25-30 mL) are collected from each patient. Blood and urine samples are then collected at 4 (±0.5) and 8 (±1) hours after contrast administration (if applicable); at 12 (±1), 24 (±2), and 48 (±2) hours after enrollment, and thereafter daily up to day 7 to day 14 while the subject is hospitalized. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are processed to plasma at the clinical site, frozen and shipped to Astute Medical, Inc., San Diego, Calif. The study urine samples are frozen and shipped to Astute Medical, Inc.

Example 4 Immunoassay Format

Analytes are measured using standard sandwich enzyme immunoassay techniques. A first antibody which binds the analyte is immobilized in wells of a 96 well polystyrene microplate. Analyte standards and test samples are pipetted into the appropriate wells and any analyte present is bound by the immobilized antibody. After washing away any unbound substances, a horseradish peroxidase-conjugated second antibody which binds the analyte is added to the wells, thereby forming sandwich complexes with the analyte (if present) and the first antibody. Following a wash to remove any unbound antibody-enzyme reagent, a substrate solution comprising tetramethylbenzidine and hydrogen peroxide is added to the wells. Color develops in proportion to the amount of analyte present in the sample. The color development is stopped and the intensity of the color is measured at 540 nm or 570 nm. An analyte concentration is assigned to the test sample by comparison to a standard curve determined from the analyte standards. Concentrations reported below are as follows: Coagulation factor VII-ng/mL, CA19-9-U/mL, Insulin-like growth factor-binding protein 7 ng/mL, C—X—C motif chemokine 6-pg/mL, and C—C motif chemokine 13-pg/mL.

Example 5 Apparently Healthy Donor and Chronic Disease Patient Samples

Human urine samples from donors with no known chronic or acute disease (“Apparently Healthy Donors”) were purchased from two vendors (Golden West Biologicals, Inc., 27625 Commerce Center Dr., Temecula, Calif. 92590 and Virginia Medical Research, Inc., 915 First Colonial Rd., Virginia Beach, Va. 23454). The urine samples were shipped and stored frozen at less than −20° C. The vendors supplied demographic information for the individual donors including gender, race (Black/White), smoking status and age.

Human urine samples from donors with various chronic diseases (“Chronic Disease Patients”) including congestive heart failure, coronary artery disease, chronic kidney disease, chronic obstructive pulmonary disease, diabetes mellitus and hypertension were purchased from Virginia Medical Research, Inc., 915 First Colonial Rd., Virginia Beach, Va. 23454. The urine samples were shipped and stored frozen at less than −20 degrees centigrade. The vendor provided a case report form for each individual donor with age, gender, race (Black/White), smoking status and alcohol use, height, weight, chronic disease(s) diagnosis, current medications and previous surgeries.

Example 6 Use of Kidney Injury Markers for Evaluating Renal Status in Patients

Patients from the intensive care unit (ICU) were enrolled in the following study. Each patient was classified by kidney status as non-injury (O), risk of injury (R), injury (I), and failure (F) according to the maximum stage reached within 7 days of enrollment as determined by the RIFLE criteria. EDTA anti-coagulated blood samples (10 mL) and a urine samples (25-30 mL) were collected from each patient at enrollment, 4 (±0.5) and 8 (±1) hours after contrast administration (if applicable); at 12 (±1), 24 (±2), and 48 (±2) hours after enrollment, and thereafter daily up to day 7 to day 14 while the subject is hospitalized. Markers were each measured by standard immunoassay methods using commercially available assay reagents in the urine samples and the plasma component of the blood samples collected.

Two cohorts were defined to represent a “diseased” and a “normal” population. While these terms are used for convenience, “diseased” and “normal” simply represent two cohorts for comparison (say RIFLE 0 vs RIFLE R, I and F; RIFLE 0 vs RIFLE R; RIFLE 0 and R vs RIFLE I and F; etc.). The time “prior max stage” represents the time at which a sample is collected, relative to the time a particular patient reaches the lowest disease stage as defined for that cohort, binned into three groups which are +/−12 hours. For example, “24 hr prior” which uses 0 vs R, 1, F as the two cohorts would mean 24 hr (+/−12 hours) prior to reaching stage R (or I if no sample at R, or F if no sample at R or I).

A receiver operating characteristic (ROC) curve was generated for each biomarker measured and the area under each ROC curve (AUC) is determined. Patients in Cohort 2 were also separated according to the reason for adjudication to cohort 2 as being based on serum creatinine measurements (sCr), being based on urine output (UO), or being based on either serum creatinine measurements or urine output. Using the same example discussed above (0 vs R, I, F), for those patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements alone, the stage 0 cohort may include patients adjudicated to stage R, I, or F on the basis of urine output; for those patients adjudicated to stage R, I, or F on the basis of urine output alone, the stage 0 cohort may include patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements; and for those patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements or urine output, the stage 0 cohort contains only patients in stage 0 for both serum creatinine measurements and urine output. Also, in the data for patients adjudicated on the basis of serum creatinine measurements or urine output, the adjudication method which yielded the most severe RIFLE stage is used.

The ability to distinguish cohort 1 from Cohort 2 was determined using ROC analysis. SE is the standard error of the AUC, n is the number of sample or individual patients (“pts,” as indicated). Standard errors are calculated as described in Hanley, J. A., and McNeil, B. J., The meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology (1982) 143: 29-36; p values are calculated with a two-tailed Z-test. An AUC <0.5 is indicative of a negative going marker for the comparison, and an AUC >0.5 is indicative of a positive going marker for the comparison.

Various threshold (or “cutoff”) concentrations were selected, and the associated sensitivity and specificity for distinguishing cohort 1 from cohort 2 are determined. OR is the odds ratio calculated for the particular cutoff concentration, and 95% CI is the confidence interval for the odds ratio.

TABLE 1 Comparison of marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and in urine samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage R, I or F in Cohort 2. Cancer Antigen 19-9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 14.7 27.5 14.7 29.5 14.7 37.5 Average 194 160 194 138 194 79.7 Stdev 1100 432 1100 429 1100 127 p(t-test) 0.84 0.72 0.61 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 11900 2270 11900 2940 11900 590 n (Samp) 122 45 122 51 122 24 n (Patient) 99 45 99 51 99 24 sCr only Median 21.9 37.2 21.9 35.1 21.9 26.5 Average 168 68.7 168 122 168 97.2 Stdev 807 102 807 213 807 172 p(t-test) 0.67 0.80 0.76 Min 1.00E−9 4.38 1.00E−9 3.94 1.00E−9 3.60 Max 11900 380 11900 758 11900 590 n (Samp) 259 12 259 19 259 12 n (Patient) 159 12 159 19 159 12 UO only Median 15.5 27.5 15.5 27.9 15.5 30.3 Average 228 166 228 134 228 53.6 Stdev 1160 442 1160 442 1160 57.8 p(t-test) 0.74 0.60 0.49 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 11900 2270 11900 2940 11900 187 n (Samp) 109 43 109 46 109 22 n (Patient) 85 43 85 46 85 22 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.58 0.58 0.55 0.60 0.61 0.55 0.60 0.57 0.54 SE 0.051 0.088 0.053 0.048 0.071 0.051 0.066 0.088 0.069 p 0.12 0.34 0.34 0.038 0.13 0.30 0.12 0.43 0.53 nCohort 1 122 259 109 122 259 109 122 259 109 nCohort 2 45 12 43 51 19 46 24 12 22 Cutoff 1 13.1 13.7 13.4 17.3 17.3 17.5 12.5 18.5 9.76 Sens 1 71% 75% 72% 71% 74% 72% 71% 75% 73% Spec 1 48% 39% 44% 56% 44% 53% 47% 46% 30% Cutoff 2 7.31 13.1 6.81 10.2 10.2 7.89 6.42 13.7 7.31 Sens 2 80% 83% 81% 80% 84% 80% 83% 83% 82% Spec 2 26% 38% 22% 37% 32% 25% 25% 39% 23% Cutoff 3 0 7.31 0 2.28 6.42 0.389 3.42 8.65 3.42 Sens 3 100%  92% 100%  90% 95% 91% 92% 92% 91% Spec 3  0% 24%  0% 17% 22%  9% 18% 29% 13% Cutoff 4 31.3 57.3 53.0 31.3 57.3 53.0 31.3 57.3 53.0 Sens 4 47% 42% 30% 49% 37% 28% 54% 25% 41% Spec 4 70% 70% 71% 70% 70% 71% 70% 70% 71% Cutoff 5 69.9 109 90.2 69.9 109 90.2 69.9 109 90.2 Sens 5 20%  8% 19% 24% 16% 20% 25% 17% 23% Spec 5 80% 80% 81% 80% 80% 81% 80% 80% 81% Cutoff 6 215 289 504 215 289 504 215 289 504 Sens 6 13%  8%  7% 10% 11%  4%  8%  8%  0% Spec 6 90% 90% 91% 90% 90% 91% 90% 90% 91% OR Quart 2 0.97 0.98 0.42 0.86 2.0 0.51 0.55 4.1 0.74 p Value 0.95 0.99 0.16 0.79 0.42 0.24 0.43 0.21 0.68 95% CI of 0.34 0.13 0.13 0.30 0.36 0.16 0.12 0.45 0.18 OR Quart2 2.8 7.2 1.4 2.5 11 1.6 2.5 38 3.1 OR Quart 3 2.0 2.0 2.8 3.0 3.2 2.4 1.8 4.1 1.2 p Value 0.17 0.42 0.036 0.024 0.16 0.073 0.36 0.21 0.78 95% CI of 0.75 0.36 1.1 1.2 0.62 0.92 0.52 0.45 0.33 OR Quart3 5.2 11 7.3 7.7 16 6.3 6.1 38 4.4 OR Quart 4 1.4 2.0 0.87 2.0 3.7 1.2 1.7 3.0 1.5 p Value 0.49 0.42 0.79 0.17 0.11 0.67 0.39 0.34 0.56 95% CI of 0.52 0.36 0.31 0.75 0.74 0.46 0.50 0.31 0.41 OR Quart4 3.9 11 2.5 5.1 19 3.4 5.8 30 5.2 C-C motif chemokine 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 2.84 4.72 2.84 5.68 2.84 4.14 Stdev 17.0 16.7 17.0 18.7 17.0 15.4 p(t-test) 0.38 0.16 0.63 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 106 214 101 214 65.2 n (Samp) 360 76 360 92 360 43 n (Patient) 190 76 190 92 190 43 sCr only Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 2.76 9.67 2.76 6.17 2.76 4.11 Stdev 15.7 32.6 15.7 17.9 15.7 12.8 p(t-test) 0.028 0.20 0.68 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 143 214 86.2 214 51.0 n (Samp) 760 29 760 37 760 23 n (Patient) 297 29 297 37 297 23 UO only Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 2.93 5.27 2.93 6.34 2.93 4.38 Stdev 17.7 18.9 17.7 19.8 17.7 15.1 p(t-test) 0.34 0.14 0.64 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 119 214 101 214 65.2 n (Samp) 317 66 317 79 317 36 n (Patient) 136 66 136 79 136 36 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.53 0.54 0.53 0.54 0.55 0.54 0.50 0.53 0.52 SE 0.037 0.056 0.040 0.034 0.050 0.037 0.047 0.062 0.051 p 0.41 0.50 0.39 0.30 0.33 0.25 1.00 0.60 0.67 nCohort 1 360 760 317 360 760 317 360 760 317 nCohort 2 76 29 66 92 37 79 43 23 36 Cutoff 1 0 0 0 0 0 0 0 0 0 Sens 1 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 1  0%  0%  0%  0%  0%  0% 0%  0%  0% Cutoff 2 0 0 0 0 0 0 0 0 0 Sens 2 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 2  0%  0%  0%  0%  0%  0% 0%  0%  0% Cutoff 3 0 0 0 0 0 0 0 0 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3  0%  0%  0%  0%  0%  0% 0%  0%  0% Cutoff 4 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 4 13% 14% 14% 14% 16% 15% 7% 13% 11% Spec 4 93% 93% 93% 93% 93% 93% 93%  93% 93% Cutoff 5 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 5 13% 14% 14% 14% 16% 15% 7% 13% 11% Spec 5 93% 93% 93% 93% 93% 93% 93%  93% 93% Cutoff 6 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 6 13% 14% 14% 14% 16% 15% 7% 13% 11% Spec 6 93% 93% 93% 93% 93% 93% 93%  93% 93% OR Quart 2 26 >29 39 41 >37 32 30 >22 22 p Value 4.4E−11 <0.0011 3.4E−9  9.3E−14 <4.2E−4    7.5E−12 5.2E−6  <0.0026 3.5E−5  95% CI of 10.0 >3.8 12 15 >5.0 12 6.9 >2.9 5.1 OR Quart2 70 na 130 110 na 85 130 na 97 OR Quart 3 0 >0 0 0 >0 0 0 >0 0 p Value na <na   na na <na   na na <na   na 95% CI of na >na   na na >na   na na >na   na OR Quart3 na na na na na na na na na OR Quart 4 2.1 >4.1 3.2 2.8 >6.2 2.6 1.5 >3.0 2.0 p Value 0.19 <0.21 0.091 0.058 <0.094 0.085 0.66 <0.34 0.42 95% CI of 0.69 >0.45 0.83 0.97 >0.73 0.88 0.25 >0.31 0.36 OR Quart4 6.4 na 12 8.2 na 7.7 9.2 na 11 C-X-C motif chemokine 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 13.2 24.1 13.2 19.1 13.2 8.72 Average 27.1 52.2 27.1 56.8 27.1 24.5 Stdev 59.3 169 59.3 127 59.3 34.7 p(t-test) 0.026 0.0012 0.78 Min 1.00E−9 0.240 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 593 1450 593 769 593 140 n (Samp) 358 75 358 92 358 43 n (Patient) 190 75 190 92 190 43 sCr only Median 15.2 28.4 15.2 19.3 15.2 9.05 Average 39.5 117 39.5 85.7 39.5 22.7 Stdev 122 310 122 182 122 26.1 p(t-test) 0.0023 0.028 0.51 Min 1.00E−9 0.240 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2500 1450 2500 769 2500 78.5 n (Samp) 758 29 758 37 758 23 n (Patient) 297 29 297 37 297 23 UO only Median 13.9 28.7 13.9 21.4 13.9 10.0 Average 27.3 56.2 27.3 63.0 27.3 28.4 Stdev 56.5 180 56.5 136 56.5 39.2 p(t-test) 0.019 3.7E−4  0.91 Min 1.00E−9 0.324 1.00E−9 0.324 1.00E−9 1.00E−9 Max 593 1450 593 769 593 140 n (Samp) 315 65 315 79 315 36 n (Patient) 136 65 136 79 136 36 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.59 0.55 0.62 0.59 0.57 0.59 0.46 0.44 0.46 SE 0.037 0.056 0.040 0.034 0.050 0.037 0.047 0.063 0.052 p 0.014 0.38 0.0032 0.013 0.19 0.010 0.40 0.35 0.49 nCohort 1 358 758 315 358 758 315 358 758 315 nCohort 2 75 29 65 92 37 79 43 23 36 Cutoff 1 7.26 5.99 9.02 7.68 9.65 10.2 4.01 5.34 4.01 Sens 1 71% 72% 71% 71% 70% 71% 72% 74% 72% Spec 1 33% 23% 36% 35% 35% 38% 22% 22% 18% Cutoff 2 4.82 2.65 6.71 5.34 5.99 5.40 3.11 4.50 3.11 Sens 2 81% 83% 80% 80% 81% 82% 81% 83% 81% Spec 2 24% 11% 27% 28% 23% 23% 16% 18% 13% Cutoff 3 2.31 1.16 3.83 2.46 2.38 2.82 1.36 2.81 1.41 Sens 3 91% 93% 91% 90% 92% 91% 91% 91% 92% Spec 3 13%  6% 17% 14% 11% 12%  9% 12%  7% Cutoff 4 22.6 28.7 25.5 22.6 28.7 25.5 22.6 28.7 25.5 Sens 4 51% 48% 54% 45% 46% 42% 30% 30% 36% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 31.4 39.8 32.1 31.4 39.8 32.1 31.4 39.8 32.1 Sens 5 40% 38% 45% 34% 32% 35% 28% 26% 33% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 51.6 64.0 53.8 51.6 64.0 53.8 51.6 64.0 53.8 Sens 6 20% 31% 15% 18% 22% 20% 16% 13% 14% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.86 0.43 0.83 1.1 0.87 0.66 0.14 0.33 0.066 p Value 0.69 0.17 0.66 0.88 0.78 0.30 0.011 0.18 0.0097 95% CI of 0.40 0.13 0.35 0.52 0.31 0.30 0.030 0.065 0.0085 OR Quart2 1.9 1.4 1.9 2.1 2.4 1.5 0.63 1.6 0.52 OR Quart 3 0.79 0.54 0.91 1.1 1.1 1.2 1.0 1.2 0.58 p Value 0.55 0.28 0.83 0.72 0.81 0.58 0.98 0.77 0.25 95% CI of 0.36 0.18 0.39 0.56 0.43 0.60 0.44 0.39 0.23 OR Quart3 1.7 1.6 2.1 2.3 3.0 2.5 2.3 3.6 1.5 OR Quart 4 2.4 1.2 2.8 2.3 1.7 2.1 1.2 1.4 1.1 p Value 0.011 0.66 0.0062 0.0094 0.27 0.035 0.66 0.58 0.81 95% CI of 1.2 0.50 1.3 1.2 0.67 1.1 0.54 0.46 0.49 OR Quart4 4.7 3.0 5.8 4.5 4.1 4.1 2.7 4.0 2.5 Coagulation factor VII 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 2.63 4.77 2.63 5.05 2.63 3.72 Average 5.27 6.37 5.27 8.73 5.27 14.0 Stdev 8.53 5.43 8.53 11.0 8.53 47.2 p(t-test) 0.39 0.0093 0.0097 Min 0.00408 0.00408 0.00408 0.00408 0.00408 0.00408 Max 65.5 20.4 65.5 63.6 65.5 249 n (Samp) 255 48 255 57 255 27 n (Patient) 103 48 103 57 103 27 sCr only Median 3.35 2.46 3.35 6.36 3.35 3.86 Average 6.76 7.40 6.76 9.71 6.76 6.19 Stdev 14.4 12.1 14.4 10.0 14.4 6.27 p(t-test) 0.86 0.35 0.89 Min 0.00408 0.00408 0.00408 0.00408 0.00408 0.00408 Max 249 48.8 249 32.3 249 23.5 n (Samp) 447 16 447 21 447 13 n (Patient) 170 16 170 21 170 13 UO only Median 2.34 5.38 2.34 4.65 2.34 3.77 Average 4.84 6.59 4.84 8.10 4.84 14.0 Stdev 8.24 5.17 8.24 10.8 8.24 49.1 p(t-test) 0.17 0.017 0.013 Min 0.00408 0.409 0.00408 0.384 0.00408 0.303 Max 65.5 20.4 65.5 63.6 65.5 249 n (Samp) 218 46 218 51 218 25 n (Patient) 87 46 87 51 87 25 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.62 0.48 0.67 0.65 0.61 0.66 0.58 0.56 0.60 SE 0.046 0.074 0.047 0.043 0.067 0.045 0.060 0.084 0.063 p 0.012 0.83 2.3E−4 5.7E−4 0.097 3.6E−4 0.16 0.49 0.10 nCohort 1 255 447 218 255 447 218 255 447 218 nCohort 2 48 16 46 57 21 51 27 13 25 Cutoff 1 1.70 1.23 3.00 2.64 3.00 2.42 2.06 2.06 1.88 Sens 1 71% 75% 72% 72% 71% 71% 70% 77% 72% Spec 1 39% 26% 57% 51% 47% 52% 43% 37% 46% Cutoff 2 1.24 0.952 1.72 2.09 2.42 1.79 1.70 1.81 1.67 Sens 2 81% 81% 80% 81% 81% 80% 81% 85% 80% Spec 2 31% 19% 43% 43% 41% 44% 39% 35% 41% Cutoff 3 0.564 0 0.704 0.906 0.692 1.23 1.10 1.72 0.952 Sens 3 92% 100%  91% 91% 90% 90% 93% 92% 92% Spec 3 15%  0% 20% 22% 14% 32% 28% 33% 24% Cutoff 4 5.19 6.42 4.32 5.19 6.42 4.32 5.19 6.42 4.32 Sens 4 48% 38% 59% 47% 48% 53% 33% 38% 32% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 7.42 9.53 7.01 7.42 9.53 7.01 7.42 9.53 7.01 Sens 5 35% 19% 41% 35% 33% 35% 26% 23% 20% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 11.5 15.3 10.1 11.5 15.3 10.1 11.5 15.3 10.1 Sens 6 19% 12% 24% 23% 24% 24% 11%  8% 16% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 1.1 0.74 1.4 1.6 1.3 2.4 4.9 5.2 1.7 p Value 0.82 0.70 0.55 0.34 0.73 0.12 0.046 0.14 0.48 95% CI of 0.41 0.16 0.44 0.61 0.33 0.80 1.0 0.60 0.39 OR Quart2 3.1 3.4 4.8 4.1 4.8 7.4 24 45 7.4 OR Quart 3 1.6 1.3 3.0 2.1 1.3 3.6 4.4 4.1 4.2 p Value 0.36 0.73 0.050 0.12 0.73 0.020 0.068 0.21 0.035 95% CI of 0.60 0.33 1.0 0.83 0.33 1.2 0.90 0.45 1.1 OR Quart3 4.1 4.8 8.9 5.2 4.8 11 21 37 16 OR Quart 4 2.8 1.0 5.7 3.4 1.8 5.2 4.3 3.1 2.1 p Value 0.025 0.99 0.0012 0.0061 0.36 0.0022 0.071 0.34 0.32 95% CI of 1.1 0.25 2.0 1.4 0.51 1.8 0.88 0.31 0.49 OR Quart4 6.9 4.1 16 8.3 6.3 15 21 30 8.7 Insulin-like growth factor-binding protein 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 45.5 70.2 45.5 72.8 45.5 42.8 Average 66.2 111 66.2 127 66.2 76.9 Stdev 69.6 104 69.6 176 69.6 76.2 p(t-test) 5.0E−6 3.1E−7 0.35 Min 1.06 8.34 1.06 5.23 1.06 4.58 Max 533 594 533 1250 533 382 n (Samp) 360 75 360 90 360 43 n (Patient) 190 75 190 90 190 43 sCr only Median 51.8 61.7 51.8 106 51.8 80.7 Average 77.0 179 77.0 167 77.0 94.5 Stdev 89.0 343 89.0 163 89.0 82.8 p(t-test) 9.0E−7 1.6E−8 0.35 Min 1.00E−9 8.34 1.00E−9 8.49 1.00E−9 4.58 Max 1250 1830 1250 674 1250 344 n (Samp) 756 29 756 37 756 23 n (Patient) 296 29 296 37 296 23 UO only Median 45.9 79.3 45.9 71.5 45.9 44.2 Average 67.4 120 67.4 135 67.4 80.6 Stdev 68.6 103 68.6 187 68.6 80.9 p(t-test) 3.9E−7 3.8E−7 0.28 Min 1.06 13.5 1.06 5.23 1.06 5.13 Max 533 594 533 1250 533 382 n (Samp) 317 65 317 77 317 36 n (Patient) 136 65 136 77 136 36 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.67 0.61 0.71 0.65 0.71 0.64 0.54 0.59 0.54 SE 0.037 0.057 0.038 0.034 0.049 0.037 0.047 0.063 0.052 p 3.0E−6 0.049 2.3E−8 1.7E−5 1.9E−5 9.5E−5 0.41 0.18 0.49 nCohort 1 360 756 317 360 756 317 360 756 317 nCohort 2 75 29 65 90 37 77 43 23 36 Cutoff 1 48.2 45.6 58.0 51.2 62.6 51.1 32.4 34.7 32.4 Sens 1 71% 72% 71% 70% 70% 70% 72% 74% 72% Spec 1 52% 44% 61% 56% 59% 55% 36% 32% 33% Cutoff 2 37.2 24.8 45.6 28.5 49.1 28.5 23.0 29.9 23.0 Sens 2 80% 83% 80% 80% 81% 81% 81% 83% 81% Spec 2 41% 23% 49% 32% 47% 29% 25% 28% 22% Cutoff 3 24.6 18.2 36.9 17.8 27.7 19.9 11.9 25.3 11.9 Sens 3 91% 93% 91% 90% 92% 91% 91% 91% 92% Spec 3 27% 16% 39% 18% 26% 16%  9% 24%  7% Cutoff 4 69.8 79.3 73.1 69.8 79.3 73.1 69.8 79.3 73.1 Sens 4 52% 48% 52% 52% 59% 49% 40% 52% 39% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 93.6 105 94.7 93.6 105 94.7 93.6 105 94.7 Sens 5 40% 41% 46% 41% 51% 43% 33% 35% 33% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 139 160 140 139 160 140 139 160 140 Sens 6 27% 31% 32% 24% 30% 25% 14% 13% 14% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 1.8 0.83 4.8 0.77 2.0 0.99 1.5 1.5 1.1 p Value 0.21 0.76 0.017 0.52 0.32 0.98 0.38 0.53 0.81 95% CI of 0.73 0.25 1.3 0.34 0.50 0.42 0.61 0.42 0.43 OR Quart2 4.2 2.8 17 1.7 8.2 2.3 3.7 5.4 2.9 OR Quart 3 2.6 1.0 7.7 2.0 3.1 1.8 0.64 0.74 0.42 p Value 0.023 1.0 0.0015 0.060 0.094 0.13 0.41 0.70 0.16 95% CI of 1.1 0.32 2.2 0.97 0.83 0.84 0.22 0.16 0.12 OR Quart3 6.0 3.2 27 3.9 12 4.0 1.9 3.4 1.4 OR Quart 4 4.2 2.1 14 3.1 6.9 3.6 1.8 2.6 1.5 p Value 4.7E−4 0.16 2.6E−5 8.1E−4 0.0022 6.6E−4 0.21 0.12 0.38 95% CI of 1.9 0.76 4.1 1.6 2.0 1.7 0.73 0.79 0.61 OR Quart4 9.3 5.6 48 6.2 24 7.5 4.2 8.3 3.7

TABLE 2 Comparison of marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R) and in urine samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage I or F in Cohort 2. Cancer Antigen 19-9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 21.9 38.2 21.9 28.5 21.9 17.7 Average 154 148 154 233 154 91.3 Stdev 810 279 810 592 810 125 p(t-test) 0.97 0.60 0.76 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 11900 1070 11900 2940 11900 371 n (Samp) 241 22 241 32 241 16 n (Patient) 159 22 159 32 159 16 sCr only Median nd nd 22.9 44.1 22.9 75.0 Average nd nd 160 46.8 160 140 Stdev nd nd 746 31.4 746 225 p(t-test) nd nd 0.71 0.94 Min nd nd 1.00E−9 3.94 1.00E−9 3.60 Max nd nd 11900 90.5 11900 645 n (Samp) nd nd 307 6 307 7 n (Patient) nd nd 186 6 186 7 UO only Median 23.1 38.2 23.1 29.3 23.1 34.8 Average 165 149 165 252 165 95.1 Stdev 863 279 863 620 863 127 p(t-test) 0.93 0.60 0.76 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 11900 1070 11900 2940 11900 371 n (Samp) 210 22 210 29 210 15 n (Patient) 132 22 132 29 132 15 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.59 nd 0.58 0.59 0.59 0.58 0.51 0.64 0.53 SE 0.066 nd 0.066 0.056 0.12 0.059 0.075 0.11 0.079 p 0.18 nd 0.25 0.097 0.48 0.15 0.87 0.22 0.67 nCohort 1 241 nd 210 241 307 210 241 307 210 nCohort 2 22 nd 22 32 6 29 16 7 15 Cutoff 1 22.6 nd 22.6 20.7 26.6 20.7 6.23 57.7 9.76 Sens 1 73% nd 73% 72% 83% 72% 75% 71% 73% Spec 1 51% nd 48% 49% 55% 46% 20% 71% 28% Cutoff 2 6.42 nd 6.42 18.5 26.6 18.5 4.76 14.2 6.23 Sens 2 82% nd 82% 81% 83% 83% 81% 86% 80% Spec 2 21% nd 19% 47% 55% 45% 17% 38% 18% Cutoff 3 0 nd 0 3.42 3.42 1.00E−9 0 3.42 0 Sens 3 100%  nd 100%  91% 100%  93% 100%  100%  100%  Spec 3  0% nd  0% 15% 15%  5%  0% 15%  0% Cutoff 4 50.1 nd 54.2 50.1 57.3 54.2 50.1 57.3 54.2 Sens 4 36% nd 36% 38% 33% 34% 44% 71% 40% Spec 4 70% nd 70% 70% 70% 70% 70% 70% 70% Cutoff 5 86.3 nd 90.2 86.3 115 90.2 86.3 115 90.2 Sens 5 27% nd 27% 28%  0% 28% 38% 14% 33% Spec 5 80% nd 80% 80% 80% 80% 80% 80% 80% Cutoff 6 227 nd 239 227 289 239 227 289 239 Sens 6 18% nd 18% 16%  0% 17% 12% 14% 13% Spec 6 90% nd 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.38 nd 0.38 1.4 0 2.1 0.79 0.99 0.74 p Value 0.25 nd 0.26 0.55 na 0.24 0.73 0.99 0.70 95% CI of 0.070 nd 0.070 0.44 na 0.60 0.20 0.061 0.16 OR Quart2 2.0 nd 2.0 4.8 na 7.4 3.1 16 3.4 OR Quart 3 1.7 nd 1.7 1.9 3.1 2.1 0.19 1.0 0.74 p Value 0.40 nd 0.38 0.27 0.33 0.24 0.13 1.0 0.70 95% CI of 0.51 nd 0.52 0.61 0.31 0.60 0.021 0.061 0.16 OR Quart3 5.4 nd 5.5 6.1 30 7.4 1.7 16 3.4 OR Quart 4 1.4 nd 1.5 2.4 2.0 2.4 1.2 4.1 1.2 p Value 0.56 nd 0.54 0.13 0.57 0.16 0.77 0.21 0.75 95% CI of 0.43 nd 0.43 0.78 0.18 0.70 0.35 0.45 0.32 OR Quart4 4.7 nd 4.9 7.3 23 8.4 4.1 38 4.9 C-C motif chemokine 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 2.76 7.45 2.76 9.69 2.76 3.39 Stdev 16.1 29.1 16.1 22.8 16.1 12.5 p(t-test) 0.10 0.0053 0.84 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 143 214 101 214 61.9 n (Samp) 694 37 694 48 694 28 n (Patient) 281 37 281 48 281 28 sCr only Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 2.95 11.8 2.95 18.4 2.95 9.44 Stdev 17.0 35.5 17.0 41.2 17.0 25.2 p(t-test) 0.13 0.0017 0.18 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 241 106 241 143 241 86.2 n (Samp) 904 9 904 13 904 13 n (Patient) 337 9 337 13 337 13 UO only Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 2.93 4.84 2.93 10.6 2.93 3.80 Stdev 17.1 24.5 17.1 24.0 17.1 13.2 p(t-test) 0.53 0.0058 0.80 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 143 214 101 214 61.9 n (Samp) 584 35 584 43 584 25 n (Patient) 209 35 209 43 209 25 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.51 0.52 0.50 0.61 0.62 0.62 0.52 0.54 0.53 SE 0.049 0.098 0.050 0.044 0.084 0.047 0.056 0.083 0.060 p 0.86 0.81 0.95 0.012 0.15 0.012 0.73 0.59 0.65 nCohort 1 694 904 584 694 904 584 694 904 584 nCohort 2 37 9 35 48 13 43 28 13 25 Cutoff 1 0 0 0 0 0 0 0 0 0 Sens 1 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 1 0%  0% 0%  0%  0%  0%  0%  0%  0% Cutoff 2 0 0 0 0 0 0 0 0 0 Sens 2 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 2 0%  0% 0%  0%  0%  0%  0%  0%  0% Cutoff 3 0 0 0 0 0 0 0 0 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3 0%  0% 0%  0%  0%  0%  0%  0%  0% Cutoff 4 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 4 8% 11% 6% 29% 31% 30% 11% 15% 12% Spec 4 93%  93% 93%  93% 93% 93% 93% 93% 93% Cutoff 5 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 5 8% 11% 6% 29% 31% 30% 11% 15% 12% Spec 5 93%  93% 93%  93% 93% 93% 93% 93% 93% Cutoff 6 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 6 8% 11% 6% 29% 31% 30% 11% 15% 12% Spec 6 93%  93% 93%  93% 93% 93% 93% 93% 93% OR Quart 2 >42 >8.3 0 >41 >9.4 35 >29 >12 >26 p Value <2.6E−4    <0.047 na <2.6E−4  <0.035 5.1E−4  <0.0010 <0.020 <0.0016 95% CI of >5.6 >1.0 na >5.6 >1.2 4.7 >3.9 >1.5 >3.4 OR Quart2 na na na na na 260 na na na OR Quart 3 >0 >0 21 >0 >0 0 >0 >0 >0 p Value <na   <na   4.1E−5  <na   <na   na <na   <na   <na   95% CI of >na   >na   4.9 >na   >na   na >na   >na   >na   OR Quart3 na na 88 na na na na na na OR Quart 4 >3.0 >1.0 0 >15 >4.1 14 >3.0 >2.0 >3.0 p Value <0.34 <1.0 na <0.0092 <0.21 0.012 <0.34 <0.57 <0.34 95% CI of >0.31 >0.062 na >2.0 >0.45 1.8 >0.31 >0.18 >0.31 OR Quart4 na na na na na 110 na na na C-X-C motif chemokine 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 13.9 34.6 13.9 41.8 13.9 13.0 Average 35.3 102 35.3 102 35.3 26.7 Stdev 119 279 119 172 119 35.5 p(t-test) 0.0028 3.3E−4  0.70 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2500 1450 2500 769 2500 140 n (Samp) 693 37 693 48 693 28 n (Patient) 281 37 281 48 281 28 sCr only Median 15.6 66.7 15.6 51.3 15.6 15.0 Average 38.5 239 38.5 168 38.5 97.8 Stdev 114 466 114 300 114 209 p(t-test) 9.4E−7  9.5E−5 0.066 Min 1.00E−9 4.70 1.00E−9  1.00E−9 1.00E−9 0.641 Max 2500 1450 2500 955 2500 769 n (Samp) 902 9 902 13 902 13 n (Patient) 337 9 337 13 337 13 UO only Median 14.9 28.4 14.9 40.8 14.9 21.2 Average 37.4 104 37.4 106 37.4 30.0 Stdev 128 287 128 180 128 37.1 p(t-test) 0.0067 1.0E−3 0.77 Min 1.00E−9 1.00E−9 1.00E−9 1.65 1.00E−9 1.00E−9 Max 2500 1450 2500 769 2500 140 n (Samp) 583 35 583 43 583 25 n (Patient) 209 35 209 43 209 25 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.64 0.75 0.63 0.72 0.70 0.71 0.49 0.53 0.52 SE 0.050 0.095 0.052 0.043 0.082 0.045 0.056 0.082 0.060 p 0.0042 0.0078 0.016 4.3E−7 0.017 3.1E−6 0.90 0.71 0.77 nCohort 1 693 902 583 693 902 583 693 902 583 nCohort 2 37 9 35 48 13 43 28 13 25 Cutoff 1 14.8 25.3 14.8 22.7 22.0 22.7 4.83 5.34 5.40 Sens 1 70% 78% 71% 71% 77% 72% 71% 77% 72% Spec 1 53% 64% 50% 67% 60% 65% 21% 21% 22% Cutoff 2 7.91 7.91 11.8 9.65 6.00 9.65 3.84 4.01 4.82 Sens 2 81% 89% 80% 81% 85% 81% 82% 85% 80% Spec 2 34% 30% 40% 39% 23% 35% 18% 16% 18% Cutoff 3 3.84 4.67 3.83 7.26 3.84 8.50 0.534 2.81 0.506 Sens 3 92% 100%  91% 92% 92% 91% 93% 92% 92% Spec 3 18% 18% 16% 30% 15% 33%  5% 12%  4% Cutoff 4 26.1 29.5 27.3 26.1 29.5 27.3 26.1 29.5 27.3 Sens 4 54% 67% 51% 58% 69% 58% 36% 38% 36% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 35.9 41.2 36.6 35.9 41.2 36.6 35.9 41.2 36.6 Sens 5 46% 67% 40% 54% 62% 53% 29% 38% 32% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 58.1 64.7 60.3 58.1 64.7 60.3 58.1 64.7 60.3 Sens 6 22% 56% 17% 38% 31% 37%  7% 31% 12% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.82 1.00 1.2 3.1 0 12 0.55 0.39 0.49 p Value 0.75 1.00 0.77 0.093 na 0.019 0.29 0.27 0.25 95% CI of 0.25 0.062 0.36 0.83 na 1.5 0.18 0.075 0.14 OR Quart2 2.7 16 4.0 12 na 92 1.7 2.0 1.7 OR Quart 3 1.2 1.00 1.4 3.1 0.66 7.3 0.43 0.20 0.49 p Value 0.78 1.00 0.56 0.093 0.65 0.065 0.17 0.14 0.25 95% CI of 0.39 0.062 0.44 0.83 0.11 0.89 0.13 0.023 0.14 OR Quart3 3.6 16 4.6 12 4.0 60 1.4 1.7 1.7 OR Quart 4 3.4 6.1 3.7 10 2.7 28 1.1 1.00 1.1 p Value 0.011 0.095 0.013 1.6E−4 0.14 0.0012 0.80 0.99 0.80 95% CI of 1.3 0.73 1.3 3.1 0.71 3.7 0.45 0.28 0.43 OR Quart4 8.7 51 10 35 10 210 2.8 3.5 3.0 Coagulation factor VII 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 2.91 4.90 2.91 4.98 2.91 3.79 Average 6.32 5.78 6.32 7.80 6.32 4.26 Stdev 14.6 4.33 14.6 6.92 14.6 3.96 p(t-test) 0.85 0.56 0.56 Min 0.00408 0.423 0.00408 0.262 0.00408 0.00408 Max 249 16.3 249 24.9 249 11.9 n (Samp) 421 25 421 33 421 17 n (Patient) 165 25 165 33 165 17 sCr only Median nd nd 3.24 4.20 3.24 6.27 Average nd nd 6.60 9.15 6.60 6.89 Stdev nd nd 13.7 8.82 13.7 6.55 p(t-test) nd nd 0.60 0.96 Min nd nd 0.00408 2.19 0.00408 0.00408 Max nd nd 249 24.9 249 19.4 n (Samp) nd nd 511 8 511 7 n (Patient) nd nd 198 8 198 7 UO only Median 2.79 5.21 2.79 4.98 2.79 3.79 Average 6.14 6.06 6.14 7.51 6.14 4.39 Stdev 15.3 4.18 15.3 6.49 15.3 3.79 p(t-test) 0.98 0.63 0.64 Min 0.00408 0.550 0.00408 0.262 0.00408 0.517 Max 249 16.3 249 19.4 249 11.9 n (Samp) 357 25 357 29 357 17 n (Patient) 135 25 135 29 135 17 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.60 nd 0.64 0.63 0.65 0.63 0.48 0.58 0.51 SE 0.061 nd 0.061 0.054 0.11 0.057 0.072 0.11 0.072 p 0.100 nd 0.022 0.015 0.16 0.028 0.79 0.48 0.84 nCohort 1 421 nd 357 421 511 357 421 511 357 nCohort 2 25 nd 25 33 8 29 17 7 17 Cutoff 1 3.28 nd 4.12 2.73 3.00 2.73 1.04 3.28 1.28 Sens 1 72% nd 72% 73% 75% 72% 71% 71% 71% Spec 1 53% nd 63% 48% 48% 50% 22% 50% 28% Cutoff 2 2.54 nd 3.28 2.16 2.42 1.43 0.837 1.81 0.906 Sens 2 80% nd 80% 82% 88% 83% 82% 86% 82% Spec 2 47% nd 55% 42% 42% 32% 18% 36% 19% Cutoff 3 0.762 nd 0.940 1.32 2.16 0.539 0.513 0 0.760 Sens 3 92% nd 92% 91% 100%  93% 94% 100%  94% Spec 3 17% nd 19% 30% 39% 11% 11%  0% 16% Cutoff 4 5.99 nd 5.61 5.99 6.42 5.61 5.99 6.42 5.61 Sens 4 36% nd 48% 45% 38% 48% 29% 43% 24% Spec 4 70% nd 70% 70% 70% 70% 70% 70% 70% Cutoff 5 8.32 nd 8.12 8.32 9.31 8.12 8.32 9.31 8.12 Sens 5 16% nd 20% 36% 38% 41% 18% 29% 18% Spec 5 80% nd 80% 80% 80% 80% 80% 80% 80% Cutoff 6 13.6 nd 12.2 13.6 14.8 12.2 13.6 14.8 12.2 Sens 6  8% nd 12% 21% 25% 28%  0% 14%  0% Spec 6 90% nd 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.74 nd 0.65 3.1 >4.1 1.5 1.3 0.99 0.58 p Value 0.69 nd 0.64 0.092 <0.21 0.53 0.72 1.00 0.47 95% CI of 0.16 nd 0.11 0.83 >0.45 0.41 0.33 0.061 0.13 OR Quart2 3.4 nd 4.0 12 na 5.6 4.9 16 2.5 OR Quart 3 2.6 nd 4.4 2.4 >1.0 1.5 0.49 3.0 1.0 p Value 0.11 nd 0.025 0.21 <1.0 0.52 0.42 0.34 1.0 95% CI of 0.80 nd 1.2 0.61 >0.062 0.42 0.088 0.31 0.28 OR Quart3 8.7 nd 16 9.6 na 5.6 2.7 30 3.6 OR Quart 4 2.1 nd 2.8 5.1 >3.0 3.6 1.5 2.0 0.78 p Value 0.25 nd 0.14 0.012 <0.34 0.032 0.51 0.57 0.72 95% CI of 0.60 nd 0.72 1.4 >0.31 1.1 0.42 0.18 0.20 OR Quart4 7.0 nd 11 18 na 11 5.6 22 3.0 Insulin-like growth factor-binding protein 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 49.6 73.9 49.6 121 49.6 76.1 Average 70.0 177 70.0 203 70.0 114 Stdev 68.7 304 68.7 224 68.7 96.5 p(t-test)  5.5E−11 5.8E−23 0.0012 Min 1.00E−9 10.3 1.00E−9 13.1 1.00E−9 8.47 Max 533 1830 533 1250 533 382 n (Samp) 691 37 691 48 691 28 n (Patient) 280 37 280 48 280 28 sCr only Median 52.7 195 52.7 204 52.7 89.5 Average 79.1 241 79.1 343 79.1 160 Stdev 90.5 170 90.5 473 90.5 144 p(t-test) 1.5E−7 1.1E−18 0.0016 Min 1.00E−9 54.6 1.00E−9 17.1 1.00E−9 26.6 Max 1250 594 1250 1830 1250 458 n (Samp) 900 9 900 13 900 13 n (Patient) 336 9 336 13 336 13 UO only Median 50.1 73.9 50.1 119 50.1 85.5 Average 71.2 173 71.2 202 71.2 122 Stdev 70.0 311 70.0 230 70.0 97.4 p(t-test) 9.2E−9 7.8E−19 5.1E−4 Min 1.00E−9 10.3 1.00E−9 13.1 1.00E−9 8.47 Max 533 1830 533 1250 533 382 n (Samp) 581 35 581 43 581 25 n (Patient) 208 35 208 43 208 25 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.69 0.86 0.67 0.78 0.82 0.77 0.65 0.72 0.68 SE 0.049 0.079 0.051 0.040 0.072 0.043 0.057 0.081 0.060 p 1.1E−4 6.1E−6 9.0E−4 2.2E−12 1.2E−5 5.3E−10 0.0088 0.0063 0.0035 nCohort 1 691 900 581 691 900 581 691 900 581 nCohort 2 37 9 35 48 13 43 28 13 25 Cutoff 1 57.5 133 55.1 83.2 85.6 79.0 51.2 69.9 51.8 Sens 1 70% 78% 71% 71% 77% 72% 71% 77% 72% Spec 1 58% 85% 55% 73% 72% 71% 51% 64% 52% Cutoff 2 46.5 68.6 39.6 65.8 73.9 65.8 34.6 54.9 47.0 Sens 2 81% 89% 80% 81% 85% 81% 82% 85% 80% Spec 2 47% 62% 38% 63% 67% 63% 33% 52% 47% Cutoff 3 33.6 54.4 33.2 41.6 62.3 41.6 26.4 34.7 28.2 Sens 3 92% 100%  91% 92% 92% 91% 93% 92% 92% Spec 3 32% 52% 30% 41% 58% 40% 26% 31% 27% Cutoff 4 76.2 82.2 77.2 76.2 82.2 77.2 76.2 82.2 77.2 Sens 4 49% 78% 49% 73% 77% 72% 50% 54% 52% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 99.9 112 99.6 99.9 112 99.6 99.9 112 99.6 Sens 5 49% 78% 46% 65% 69% 63% 36% 38% 44% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 146 163 147 146 163 147 146 163 147 Sens 6 41% 56% 37% 40% 54% 37% 29% 38% 32% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 2.0 >0 2.4 1.7 0 1.0 3.1 1.0 2.5 p Value 0.32 <na   0.21 0.48 na 1.0 0.18 1.0 0.27 95% CI of 0.50 >na   0.61 0.39 na 0.25 0.61 0.062 0.48 OR Quart2 8.3 na 9.4 7.1 na 4.1 15 16 13 OR Quart 3 3.5 >2.0 2.8 2.7 3.0 1.8 4.1 5.1 3.1 p Value 0.062 <0.57 0.14 0.14 0.34 0.36 0.076 0.14 0.17 95% CI of 0.94 >0.18 0.72 0.71 0.31 0.51 0.86 0.59 0.61 OR Quart3 13 na 11 10 29 6.2 20 44 16 OR Quart 4 6.5 >7.2 6.2 13 9.3 8.3 6.3 6.1 6.4 p Value 0.0030 <0.066 0.0040 3.6E−5  0.035 1.1E−4  0.017 0.095 0.016 95% CI of 1.9 >0.88 1.8 3.8 1.2 2.8 1.4 0.73 1.4 OR Quart4 23 na 22 42 74 24 29 51 29

TABLE 3 Comparison of marker levels in urine samples collected within 12 hours of reaching stage R from Cohort 1 (patients that reached, but did not progress beyond, RIFLE stage R) and from Cohort 2 (patients that reached RIFLE stage I or F). Coagulation factor VII sCr or UO sCr only UO only Cohort Cohort Cohort Cohort Cohort Cohort 1 2 1 2 1 2 Median 4.15 4.98 1.42 2.19 5.74 6.35 Average 5.72 6.64 3.27 4.92 6.37 8.23 Stdev 5.41 6.33 3.88 5.72 5.35 6.91 p(t-test) 0.52 0.41 0.28 Min 0.00408 0.535 0.00408 0.842 0.409 0.423 Max 20.4 19.1 14.7 16.8 20.4 19.1 n (Samp) 52 23 18 7 43 16 n (Patient) 52 23 18 7 43 16 At Enrollment sCr or UO sCr only UO only AUC 0.53 0.60 0.56 SE 0.073 0.13 0.086 p 0.66 0.43 0.48 nCohort 1 52 18 43 nCohort 2 23 7 16 Cutoff 1 1.45 1.45 2.87 Sens 1 74% 71% 75% Spec 1 31% 56% 37% Cutoff 2 0.842 0.842 1.68 Sens 2 83% 86% 81% Spec 2 15% 22% 26% Cutoff 3 0.837 0.536 0.423 Sens 3 91% 100%  94% Spec 3 15% 22%  2% Cutoff 4 8.08 4.03 8.49 Sens 4 30% 43% 38% Spec 4 71% 72% 72% Cutoff 5 10.3 6.57 10.9 Sens 5 26% 29% 38% Spec 5 81% 83% 81% Cutoff 6 13.9 8.82 13.9 Sens 6 17% 14% 25% Spec 6 90% 94% 91% OR Quart 2 0.93 0 1.8 p Value 0.92 na 0.48 95% CI of 0.22 na 0.35 OR Quart2 4.0 na 9.7 OR Quart 3 1.5 1.0 0.56 p Value 0.56 1.0 0.57 95% CI of 0.38 0.091 0.079 OR Quart3 6.1 11 4.0 OR Quart 4 1.2 1.5 2.4 p Value 0.80 0.73 0.29 95% CI of 0.29 0.16 0.47 OR Quart4 4.9 14 13

TABLE 4 Comparison of the maximum marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and the maximum values in urine samples collected from subjects between enrollment and 0, 24 hours, and 48 hours prior to reaching stage F in Cohort 2. Cancer Antigen 19-9 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 16.8 92.7 16.8 75.2 16.8 91.1 Average 221 364 221 349 221 72.0 Stdev 1220 831 1220 835 1220 41.9 p (t-test) 0.69 0.72 0.75 Min 1.00E−9 6.68 1.00E−9 6.68 1.00E−9 16.2 Max 11900 2940 11900 2940 11900 125 n (Samp) 99 12 99 12 99 7 n (Patient) 99 12 99 12 99 7 sCr only Median 24.5 95.3 24.5 72.2 nd nd Average 230 184 230 155 nd nd Stdev 1020 235 1020 242 nd nd p (t-test) 0.91 0.86 nd nd Min 1.00E−9 6.68 1.00E−9 6.68 nd nd Max 11900 645 11900 645 nd nd n (Samp) 159 6 159 6 nd nd n (Patient) 159 6 159 6 nd nd UO only Median 18.5 96.9 18.5 96.9 18.5 76.8 Average 263 501 263 501 263 68.8 Stdev 1310 1010 1310 1010 1310 45.0 p (t-test) 0.62 0.62 0.72 Min 1.00E−9 18.6 1.00E−9 18.6 1.00E−9 16.2 Max 11900 2940 11900 2940 11900 125 n (Samp) 85 8 85 8 85 6 n (Patient) 85 8 85 8 85 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.75 0.69 0.76 0.73 0.64 0.76 0.73 nd 0.68 SE 0.085 0.12 0.10 0.086 0.12 0.10 0.11 nd 0.12 p 0.0038 0.13 0.012 0.0079 0.25 0.012 0.036 nd 0.15 nCohort 1 99 159 85 99 159 85 99 nd 85 nCohort 2 12 6 8 12 6 8 7 nd 6 Cutoff 1 50.1 50.8 57.4 33.3 33.3 57.4 57.4 nd 18.5 Sens 1 75% 83% 75% 75% 83% 75% 71% nd 83% Spec 1 73% 65% 72% 69% 59% 72% 75% nd 51% Cutoff 2 20.4 50.8 19.7 20.4 33.3 19.7 18.5 nd 18.5 Sens 2 83% 83% 88% 83% 83% 88% 86% nd 83% Spec 2 57% 65% 53% 57% 59% 53% 54% nd 51% Cutoff 3 18.5 6.42 18.5 18.5 6.42 18.5 16.1 nd 15.3 Sens 3 92% 100%  100%  92% 100%  100%  100%  nd 100%  Spec 3 54% 18% 51% 54% 18% 51% 49% nd 46% Cutoff 4 43.0 66.9 55.3 43.0 66.9 55.3 43.0 nd 55.3 Sens 4 75% 67% 75% 67% 50% 75% 71% nd 67% Spec 4 71% 70% 71% 71% 70% 71% 71% nd 71% Cutoff 5 76.6 125 114 76.6 125 114 76.6 nd 114 Sens 5 58% 33% 38% 50% 17% 38% 57% nd 17% Spec 5 81% 81% 80% 81% 81% 80% 81% nd 80% Cutoff 6 227 396 504 227 396 504 227 nd 504 Sens 6 17% 17% 25% 17% 17% 25%  0% nd  0% Spec 6 91% 91% 91% 91% 91% 91% 91% nd 91% OR Quart 2 0.96 0 >1.0 0.96 0 >1.0 >1.0 nd >2.1 p Value 0.98 na <0.98 0.98 na <0.98 <1.0 nd <0.56 95% CI of 0.057 na >0.062 0.057 na >0.062 >0.059 nd >0.18 OR Quart 2 16 na na 16 na na na nd na OR Quart 3 3.1 2.1 >2.2 4.3 2.1 >2.2 >2.2 nd >1.0 p Value 0.34 0.56 <0.53 0.20 0.56 <0.53 <0.54 nd <1.0 95% CI of 0.30 0.18 >0.18 0.45 0.18 >0.18 >0.18 nd >0.059 OR Quart 3 32 24 na 42 24 na na nd na OR Quart 4 8.7 3.1 >6.1 7.1 3.1 >6.1 >4.5 nd >3.3 p Value 0.051 0.34 <0.11 0.080 0.34 <0.11 <0.19 nd <0.32 95% CI of 0.99 0.31 >0.65 0.79 0.31 >0.65 >0.47 nd >0.32 OR Quart 4 76 31 na 63 31 na na nd na C-C motif chemokine 13 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 3.50 22.9 3.50 20.2 3.50 11.9 Stdev 19.2 39.5 19.2 32.1 19.2 20.8 p (t-test)  1.6E−4  5.8E−4 0.16 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 143 214 101 214 64.7 n (Samp) 190 21 190 21 190 11 n (Patient) 190 21 190 21 190 11 sCr only Median 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Average 5.03 18.9 5.03 9.33 5.03 1.17 Stdev 21.5 33.8 21.5 18.1 21.5 2.87 p (t-test) 0.041 0.51 0.66 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 106 214 55.1 214 7.03 n (Samp) 297 11 297 11 297 6 n (Patient) 297 11 297 11 297 6 UO only Median 1.00E−9 7.03 1.00E−9 7.03 1.00E−9 7.03 Average 4.07 29.4 4.07 25.6 4.07 14.6 Stdev 21.9 44.8 21.9 36.0 21.9 22.2 p (t-test)  2.7E−4  1.0E−3 0.17 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 214 143 214 101 214 64.7 n (Samp) 136 15 136 15 136 9 n (Patient) 136 15 136 15 136 9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.69 0.67 0.72 0.69 0.62 0.72 0.68 0.51 0.73 SE 0.066 0.091 0.077 0.067 0.092 0.077 0.091 0.12 0.098 p 0.0034 0.067 0.0038 0.0035 0.20 0.0039 0.050 0.91 0.021 nCohort 1 190 297 136 190 297 136 190 297 136 nCohort 2 21 11 15 21 11 15 11 6 9 Cutoff 1 0 0 0 0 0 0 0 0 0 Sens 1 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 1  0%  0%  0%  0%  0%  0%  0%  0%  0% Cutoff 2 0 0 0 0 0 0 0 0 0 Sens 2 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 2  0%  0%  0%  0%  0%  0%  0%  0%  0% Cutoff 3 0 0 0 0 0 0 0 0 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3  0%  0%  0%  0%  0%  0%  0%  0%  0% Cutoff 4 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 4 48% 45% 53% 48% 36% 53% 45% 17% 56% Spec 4 90% 88% 90% 90% 88% 90% 90% 88% 90% Cutoff 5 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Sens 5 48% 45% 53% 48% 36% 53% 45% 17% 56% Spec 5 90% 88% 90% 90% 88% 90% 90% 88% 90% Cutoff 6 1.00E−9 7.03 4.08 1.00E−9 7.03 4.08 1.00E−9 7.03 4.08 Sens 6 48% 27% 53% 48% 18% 53% 45%  0% 56% Spec 6 90% 92% 90% 90% 92% 90% 90% 92% 90% OR Quart 2 12 5.3 >8.4 12 6.4 >8.4 5.4 4.1 >4.5 p Value 0.021 0.13 <0.053 0.021 0.089 <0.053 0.13 0.21 <0.19 95% CI of 1.5 0.60 >0.97 1.5 0.75 >0.97 0.61 0.45 >0.48 OR Quart 2 96 46 na 96 55 na 48 38 na OR Quart 3 0 0 >0 0 0 >0 0 0 >0 p Value na na <na na na <na na na <na 95% CI of na na >na na na >na na na >na OR Quart 3 na na na na na na na na na OR Quart 4 12 5.3 >9.9 12 4.2 >9.9 5.3 0.99 >5.6 p Value 0.021 0.13 <0.036 0.021 0.21 <0.036 0.13 0.99 <0.12 95% CI of 1.5 0.60 >1.2 1.5 0.45 >1.2 0.60 0.061 >0.62 OR Quart 4 96 46 na 96 38 na 47 16 na C—X—C motif chemokine 6 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 14.8 61.3 14.8 51.3 14.8 37.9 Average 34.0 241 34.0 163 34.0 64.9 Stdev 74.0 382 74.0 232 74.0 66.9 p (t-test) 4.8E−10 7.8E−8 0.18 Min 1.00E−9 5.30 1.00E−9 1.62 1.00E−9 8.72 Max 593 1450 593 769 593 172 n (Samp) 190 21 190 21 190 11 n (Patient) 190 21 190 21 190 11 sCr only Median 21.0 53.8 21.0 51.3 21.0 52.6 Average 57.2 253 57.2 171 57.2 182 Stdev 172 452 172 282 172 292 p (t-test) 7.5E−4 0.036 0.083 Min 1.00E−9 5.30 1.00E−9 1.62 1.00E−9 17.6 Max 2500 1450 2500 769 2500 769 n (Samp) 297 11 297 11 297 6 n (Patient) 297 11 297 11 297 6 UO only Median 17.8 163 17.8 114 17.8 24.7 Average 36.8 323 36.8 216 36.8 69.1 Stdev 76.2 428 76.2 256 76.2 74.0 p (t-test) 7.5E−11 6.3E−9 0.22 Min 1.00E−9 9.04 1.00E−9 9.04 1.00E−9 8.72 Max 593 1450 593 769 593 172 n (Samp) 136 15 136 15 136 9 n (Patient) 136 15 136 15 136 9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.79 0.71 0.82 0.77 0.67 0.81 0.71 0.77 0.65 SE 0.060 0.089 0.068 0.062 0.091 0.069 0.090 0.11 0.10 p 1.3E−6 0.017 2.7E−6 1.8E−5 0.066 5.7E−6 0.018 0.016 0.14 nCohort 1 190 297 136 190 297 136 190 297 136 nCohort 2 21 11 15 21 11 15 11 6 9 Cutoff 1 33.0 33.0 47.5 24.0 22.0 47.5 17.6 37.6 14.3 Sens 1 71% 73% 73% 71% 73% 73% 73% 83% 78% Spec 1 75% 64% 82% 66% 53% 82% 56% 69% 43% Cutoff 2 17.6 17.6 23.5 17.6 17.6 23.5 14.3 37.6 9.02 Sens 2 81% 82% 80% 81% 82% 80% 82% 83% 89% Spec 2 56% 45% 61% 56% 45% 61% 49% 69% 30% Cutoff 3 11.5 11.5 11.9 11.5 11.5 11.9 9.03 17.6 8.41 Sens 3 90% 91% 93% 90% 91% 93% 91% 100%  100%  Spec 3 43% 32% 38% 43% 32% 38% 36% 45% 29% Cutoff 4 27.0 38.6 30.7 27.0 38.6 30.7 27.0 38.6 30.7 Sens 4 71% 64% 73% 67% 55% 73% 55% 67% 44% Spec 4 70% 70% 71% 70% 70% 71% 70% 70% 71% Cutoff 5 39.8 53.3 39.8 39.8 53.3 39.8 39.8 53.3 39.8 Sens 5 67% 55% 73% 62% 45% 73% 45% 50% 44% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 57.9 111 68.0 57.9 111 68.0 57.9 111 68.0 Sens 6 52% 36% 60% 43% 27% 60% 27% 33% 33% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 3.1 2.0 >3.2 3.1 2.0 >3.2 >3.2 >1.0 >4.5 p Value 0.34 0.57 <0.33 0.34 0.57 <0.33 <0.32 <1.0 <0.19 95% CI of 0.31 0.18 >0.31 0.31 0.18 >0.31 >0.32 >0.061 >0.48 OR Quart 2 30 23 na 30 23 na na na na OR Quart 3 3.1 2.0 >1.0 4.2 2.0 >1.0 >2.1 >1.0 >1.0 p Value 0.34 0.57 <1.0 0.21 0.57 <1.0 <0.55 <1.0 <0.98 95% CI of 0.31 0.18 >0.060 0.45 0.18 >0.060 >0.18 >0.061 >0.062 OR Quart 3 30 23 na 39 23 na na na na OR Quart 4 18 6.4 >15 17 6.4 >15 >6.7 >4.2 >4.4 p Value 0.0059 0.089 <0.012 0.0080 0.089 <0.012 <0.084 <0.21 <0.20 95% CI of 2.3 0.75 >1.8 2.1 0.75 >1.8 >0.77 >0.45 >0.46 OR Quart 4 150 55 na 130 55 na na na na Coagulation factor VII 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 4.12 7.44 4.12 7.41 4.12 5.89 Average 8.33 12.6 8.33 10.3 8.33 8.14 Stdev 12.0 12.2 12.0 8.04 12.0 7.18 p (t-test) 0.19 0.55 0.96 Min 0.00408 0.491 0.00408 0.348 0.00408 3.18 Max 65.5 48.8 65.5 24.9 65.5 24.8 n (Samp) 103 16 103 15 103 8 n (Patient) 103 16 103 15 103 8 sCr only Median 5.99 13.4 5.99 13.2 nd nd Average 10.7 17.2 10.7 13.4 nd nd Stdev 21.3 15.8 21.3 9.62 nd nd p (t-test) 0.40 0.72 nd nd Min 0.00408 0.491 0.00408 0.348 nd nd Max 249 48.8 249 24.9 nd nd n (Samp) 170 8 170 8 nd nd n (Patient) 170 8 170 8 nd nd UO only Median 3.83 7.44 3.83 7.41 3.83 4.54 Average 7.81 9.13 7.81 8.15 7.81 5.64 Stdev 11.9 5.61 11.9 5.33 11.9 2.93 p (t-test) 0.73 0.93 0.66 Min 0.00408 3.48 0.00408 3.18 0.00408 3.18 Max 65.5 19.4 65.5 19.4 65.5 10.7 n (Samp) 87 10 87 9 87 6 n (Patient) 87 10 87 9 87 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.68 0.67 0.70 0.65 0.65 0.66 0.62 nd 0.58 SE 0.078 0.11 0.096 0.081 0.11 0.10 0.11 nd 0.13 p 0.020 0.12 0.039 0.063 0.16 0.12 0.29 nd 0.51 nCohort 1 103 170 87 103 170 87 103 nd 87 nCohort 2 16 8 10 15 8 9 8 nd 6 Cutoff 1 5.28 6.42 5.28 5.28 6.42 3.72 3.72 nd 3.31 Sens 1 75% 75% 70% 73% 75% 78% 75% nd 83% Spec 1 57% 54% 61% 57% 54% 49% 48% nd 46% Cutoff 2 4.32 5.29 4.32 3.72 5.29 3.31 3.31 nd 3.31 Sens 2 81% 88% 80% 80% 88% 89% 88% nd 83% Spec 2 53% 46% 56% 48% 46% 46% 43% nd 46% Cutoff 3 3.31 0.435 3.72 3.07 0.313 3.07 3.07 nd 3.07 Sens 3 94% 100%  90% 93% 100%  100%  100%  nd 100%  Spec 3 43%  4% 49% 40%  1% 43% 40% nd 43% Cutoff 4 7.83 10.3 7.42 7.83 10.3 7.42 7.83 nd 7.42 Sens 4 44% 50% 50% 40% 50% 44% 25% nd 17% Spec 4 71% 71% 70% 71% 71% 70% 71% nd 70% Cutoff 5 12.8 14.3 10.1 12.8 14.3 10.1 12.8 nd 10.1 Sens 5 31% 50% 40% 27% 50% 33% 12% nd 17% Spec 5 81% 80% 80% 81% 80% 80% 81% nd 80% Cutoff 6 19.4 21.0 17.3 19.4 21.0 17.3 19.4 nd 17.3 Sens 6 19% 38% 10% 13% 25% 11% 12% nd  0% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 3.1 0.98 >2.2 3.1 0.98 >3.4 >3.2 nd >3.4 p Value 0.34 0.99 <0.54 0.34 0.99 <0.30 <0.32 nd <0.30 95% CI of 0.30 0.059 >0.18 0.30 0.059 >0.33 >0.32 nd >0.33 OR Quart 2 32 16 na 32 16 na na nd na OR Quart 3 5.6 2.0 >4.8 5.8 2.0 >3.4 >3.2 nd >2.2 p Value 0.13 0.56 <0.18 0.12 0.56 <0.30 <0.32 nd <0.53 95% CI of 0.61 0.18 >0.50 0.64 0.18 >0.33 >0.32 nd >0.18 OR Quart 3 51 23 na 53 23 na na nd na OR Quart 4 8.5 4.2 >4.6 7.0 4.2 >3.4 >2.1 nd >1.0 p Value 0.053 0.21 <0.19 0.081 0.21 <0.30 <0.56 nd <1.0 95% CI of 0.98 0.45 >0.47 0.79 0.45 >0.33 >0.18 nd >0.059 OR Quart 4 74 39 na 62 39 na na nd na Insulin-like growth factor-binding protein 7 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 54.4 210 54.4 206 54.4 165 Average 77.4 379 77.4 297 77.4 173 Stdev 79.3 440 79.3 285 79.3 92.7 p (t-test) 5.8E−15 1.8E−14 1.7E−4 Min 1.93 27.2 1.93 23.1 1.93 53.6 Max 533 1830 533 1250 533 382 n (Samp) 190 21 190 21 190 11 n (Patient) 190 21 190 21 190 11 sCr only Median 74.0 210 74.0 206 74.0 208 Average 109 314 109 215 109 232 Stdev 119 320 119 153 119 141 p (t-test) 5.7E−7  0.0044 0.013 Min 1.93 27.2 1.93 23.1 1.93 53.6 Max 1250 1120 1250 458 1250 458 n (Samp) 296 11 296 11 296 6 n (Patient) 296 11 296 11 296 6 UO only Median 61.2 247 61.2 247 61.2 165 Average 85.1 468 85.1 362 85.1 182 Stdev 81.9 490 81.9 308 81.9 93.3 p (t-test) 5.3E−14 5.4E−14 8.9E−4 Min 1.93 80.7 1.93 80.7 1.93 80.7 Max 533 1830 533 1250 533 382 n (Samp) 136 15 136 15 136 9 n (Patient) 136 15 136 15 136 9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.85 0.74 0.91 0.84 0.72 0.91 0.84 0.80 0.85 SE 0.054 0.087 0.051 0.055 0.089 0.052 0.076 0.11 0.082 p 1.2E−10 0.0065 1.3E−15 4.1E−10 0.013 2.9E−15 7.3E−6 0.0061 2.4E−5 nCohort 1 190 296 136 190 296 136 190 296 136 nCohort 2 21 11 15 21 11 15 11 6 9 Cutoff 1 145 145 163 140 140 163 103 145 103 Sens 1 71% 73% 73% 71% 73% 73% 73% 83% 78% Spec 1 89% 78% 90% 88% 77% 90% 77% 78% 73% Cutoff 2 103 53.2 145 103 53.2 145 100 145 100 Sens 2 81% 82% 80% 81% 82% 80% 82% 83% 89% Spec 2 77% 36% 87% 77% 36% 87% 75% 78% 71% Cutoff 3 53.2 39.0 103 53.2 39.0 103 76.5 53.2 76.4 Sens 3 90% 91% 93% 90% 91% 93% 91% 100%  100%  Spec 3 49% 24% 73% 49% 24% 73% 65% 36% 59% Cutoff 4 91.1 114 99.6 91.1 114 99.6 91.1 114 99.6 Sens 4 81% 73% 93% 81% 73% 93% 82% 83% 89% Spec 4 70% 70% 71% 70% 70% 71% 70% 70% 71% Cutoff 5 114 154 127 114 154 127 114 154 127 Sens 5 76% 64% 80% 76% 55% 80% 64% 67% 67% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 151 257 172 151 257 172 151 257 172 Sens 6 67% 36% 67% 62% 36% 67% 55% 33% 44% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 2.0 0.49 >0 2.0 0.49 >0 >1.0 >1.0 >0 p Value 0.58 0.56 <na 0.58 0.56 <na <0.99 <1.0 <na 95% CI of 0.18 0.043 >na 0.18 0.043 >na >0.062 >0.061 >na OR Quart 2 23 5.5 na 23 5.5 na na na na OR Quart 3 2.0 0 >3.2 2.0 0 >3.2 >3.2 >0 >3.3 p Value 0.58 na <0.33 0.58 na <0.33 <0.32 <na <0.31 95% CI of 0.18 na >0.31 0.18 na >0.31 >0.32 >na >0.32 OR Quart 3 23 na na 23 na na na na na OR Quart 4 22 4.3 >17 22 4.3 >17 >8.0 >5.3 >7.0 p Value 0.0033 0.072 <0.0081 0.0033 0.072 <0.0081 <0.057 <0.13 <0.080 95% CI of 2.8 0.88 >2.1 2.8 0.88 >2.1 >0.94 >0.60 >0.79 OR Quart 4 170 21 na 170 21 na na na na

TABLE 5 Comparison of marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and in EDTA samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage R, I or F in Cohort 2. Cancer Antigen 19-9 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.204 0.311 0.204 0.316 0.204 0.205 Average 0.320 0.631 0.320 0.804 0.320 0.486 Stdev 0.642 0.759 0.642 1.07 0.642 0.749 p (t-test) 0.023 0.0019 0.27 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 5.30 2.79 5.30 5.26 5.30 2.83 n (Samp) 81 37 81 45 81 26 n (Patient) 74 37 74 45 74 26 sCr only Median 0.244 0.333 0.244 0.695 0.244 0.228 Average 0.466 0.735 0.466 3.65 0.466 0.763 Stdev 0.757 0.824 0.757 10.9 0.757 1.08 p (t-test) 0.24  6.4E−5 0.26 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 5.30 2.77 5.30 41.6 5.30 2.83 n (Samp) 197 12 197 14 197 9 n (Patient) 131 12 131 14 131 9 UO only Median 0.244 0.311 0.244 0.285 0.244 0.228 Average 0.484 0.563 0.484 0.738 0.484 0.334 Stdev 0.774 0.703 0.774 1.05 0.774 0.432 p (t-test) 0.63 0.13 0.40 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 5.30 2.79 5.30 5.26 5.30 1.94 n (Samp) 77 29 77 43 77 21 n (Patient) 64 29 64 43 64 21 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCR only UO only AUC 0.65 0.62 0.55 0.67 0.69 0.58 0.53 0.54 0.45 SE 0.056 0.089 0.064 0.052 0.081 0.055 0.066 0.10 0.072 p 0.0075 0.16 0.46 7.8E−4 0.018 0.16 0.62 0.69 0.48 nCohort 1 81 197 77 81 197 77 81 197 77 nCohort 2 37 12 29 45 14 43 26 9 21 Cutoff 1 0.204 0.204 0.134 0.204 0.244 0.182 0.0851 0.134 0.0842 Sens 1 70% 75% 72% 71% 71% 72% 73% 78% 71% Spec 1 53% 43% 29% 53% 52% 39% 28% 30% 22% Cutoff 2 0.124 0.198 0.0783 0.174 0.175 0.134 0.0291 0.124 0.0291 Sens 2 81% 83% 83% 80% 93% 81% 85% 89% 86% Spec 2 35% 41% 14% 43% 36% 29% 15% 30% 10% Cutoff 3 1.00E−9 0.124 0 0.00741 0.175 1.00E−9 0 0 1.00E−9 Sens 3 92% 92% 100%  91% 93% 91% 100%  100%  90% Spec 3 10% 30%  0% 14% 36%  9%  0%  0%  9% Cutoff 4 0.308 0.405 0.401 0.308 0.405 0.401 0.308 0.405 0.401 Sens 4 51% 50% 45% 51% 57% 44% 42% 33% 29% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 0.357 0.590 0.633 0.357 0.590 0.633 0.357 0.590 0.633 Sens 5 49% 42% 24% 49% 57% 30% 31% 33% 14% Spec 5 80% 81% 81% 80% 81% 81% 80% 81% 81% Cutoff 6 0.614 0.944 1.27 0.614 0.944 1.27 0.614 0.944 1.27 Sens 6 27% 33% 14% 40% 29% 19% 19% 22%  5% Spec 6 90% 90% 91% 90% 90% 91% 90% 90% 91% OR Quart 2 1.2 4.2 0.78 1.9 3.1 1.8 0.78 4.2 1.8 p Value 0.81 0.20 0.69 0.28 0.34 0.28 0.69 0.21 0.44 95% CI of 0.34 0.46 0.22 0.59 0.31 0.62 0.22 0.45 0.43 OR Quart 2 4.0 39 2.7 6.1 30 5.5 2.7 39 7.2 OR Quart 3 1.5 2.0 1.0 1.7 2.0 1.4 0.47 1.0 1.3 p Value 0.54 0.57 1.0 0.38 0.58 0.57 0.28 1.0 0.71 95% CI of 0.43 0.18 0.29 0.52 0.18 0.45 0.12 0.061 0.31 OR Quart 3 4.9 23 3.4 5.6 23 4.2 1.9 16 5.6 OR Quart 4 4.4 5.3 1.4 6.9 9.1 2.1 1.4 3.1 1.8 p Value 0.012 0.13 0.61 8.9E−4 0.041 0.18 0.61 0.34 0.44 95% CI of 1.4 0.60 0.42 2.2 1.1 0.71 0.42 0.31 0.43 OR Quart 4 14 47 4.4 22 75 6.2 4.4 30 7.2 C-C motif chemokine 13 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 21.0 1.00E−9 21.0 22.6 21.0 49.4 Average 102 42.7 102 49.6 102 60.4 Stdev 364 79.8 364 72.1 364 63.8 p (t-test) 0.39 0.41 0.64 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2520 361 2520 279 2520 284 n (Samp) 52 29 52 34 52 18 n (Patient) 50 29 50 34 50 18 sCr only Median 8.21 54.8 8.21 44.2 8.21 54.3 Average 58.9 92.4 58.9 101 58.9 76.7 Stdev 235 121 235 180 235 87.9 p (t-test) 0.66 0.47 0.83 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2520 361 2520 713 2520 284 n (Samp) 132 10 132 17 132 8 n (Patient) 100 10 100 17 100 8 UO only Median 21.0 1.00E−9 21.0 1.00E−9 21.0 38.0 Average 109 13.6 109 33.2 109 39.5 Stdev 362 21.9 362 48.9 362 35.5 p (t-test) 0.21 0.26 0.49 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2520 62.8 2520 186 2520 96.3 n (Samp) 53 23 53 30 53 13 n (Patient) 46 23 46 30 46 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCR only UO only AUC 0.44 0.63 0.32 0.49 0.59 0.43 0.64 0.71 0.54 SE 0.067 0.098 0.070 0.064 0.076 0.066 0.079 0.11 0.091 p 0.36 0.19 0.010 0.92 0.22 0.28 0.076 0.043 0.69 nCohort 1 52 132 53 52 132 53 52 132 53 nCohort 2 29 10 23 34 17 30 18 8 13 Cutoff 1 0 0 0 0 0 0 23.9 38.0 7.19 Sens 1 100%  100%  100%  100%  100%  100%  72% 75% 77% Spec 1  0%  0%  0%  0%  0%  0% 58% 64% 42% Cutoff 2 0 0 0 0 0 0 7.19 21.8 0 Sens 2 100%  100%  100%  100%  100%  100%  89% 88% 100%  Spec 2  0%  0%  0%  0%  0%  0% 44% 58%  0% Cutoff 3 0 0 0 0 0 0 0 0 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  100%  100%  Spec 3  0%  0%  0%  0%  0%  0%  0%  0%  0% Cutoff 4 56.0 44.2 62.8 56.0 44.2 62.8 56.0 44.2 62.8 Sens 4 17% 60%  0% 29% 47% 20% 39% 62% 31% Spec 4 71% 72% 72% 71% 72% 72% 71% 72% 72% Cutoff 5 72.2 59.5 72.2 72.2 59.5 72.2 72.2 59.5 72.2 Sens 5 14% 40%  0% 21% 41% 17% 28% 38% 23% Spec 5 81% 80% 81% 81% 80% 81% 81% 80% 81% Cutoff 6 105 92.0 105 105 92.0 105 105 92.0 105 Sens 6 10% 40%  0% 15% 24% 13%  6% 12%  0% Spec 6 90% 90% 91% 90% 90% 91% 90% 90% 91% OR Quart 2 1.3 0 3.0 0.60 >10 1.2 4.6 0 4.6 p Value 0.66 na 0.22 0.42 <0.033 0.74 0.20 na 0.20 95% CI of 0.36 na 0.51 0.17 >1.2 0.34 0.46 na 0.46 OR Quart 2 5.0 na 18 2.1 na 4.6 46 na 47 OR Quart 3 2.0 0.23 9.4 1.0 >1.0 2.3 8.7 4.4 5.0 p Value 0.28 0.20 0.010 1.0 <0.98 0.21 0.059 0.20 0.17 95% CI of 0.56 0.024 1.7 0.31 >0.062 0.63 0.92 0.46 0.49 OR Quart 3 7.5 2.2 53 3.3 na 8.1 83 41 51 OR Quart 4 1.3 1.2 3.9 0.60 >9.9 1.3 10 3.2 4.6 p Value 0.66 0.76 0.13 0.42 <0.036 0.66 0.042 0.33 0.20 95% CI of 0.36 0.31 0.68 0.17 >1.2 0.36 1.1 0.32 0.46 OR Quart 4 5.0 5.1 23 2.1 na 5.0 95 32 47 C—X—C motif chemokine 6 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 31.8 31.0 31.8 36.4 31.8 17.0 Average 49.0 49.8 49.0 51.5 49.0 32.9 Stdev 48.9 51.8 48.9 61.6 48.9 36.7 p (t-test) 0.95 0.84 0.21 Min 5.55 3.49 5.55 4.02 5.55 6.54 Max 244 244 244 311 244 144 n (Samp) 53 29 53 34 53 18 n (Patient) 51 29 51 34 51 18 sCr only Median 26.4 31.9 26.4 44.1 26.4 28.4 Average 45.1 46.7 45.1 70.0 45.1 47.5 Stdev 52.8 41.5 52.8 79.0 52.8 48.3 p (t-test) 0.92 0.087 0.90 Min 3.49 10.7 3.49 8.88 3.49 9.55 Max 311 129 311 336 311 144 n (Samp) 133 10 133 17 133 8 n (Patient) 101 10 101 17 101 8 UO only Median 31.3 29.1 31.3 36.4 31.3 19.6 Average 45.1 46.5 45.1 52.1 45.1 25.7 Stdev 46.6 53.4 46.6 65.3 46.6 19.2 p (t-test) 0.91 0.57 0.15 Min 5.55 3.49 5.55 4.02 5.55 6.54 Max 244 244 244 311 244 66.2 n (Samp) 54 23 54 30 54 13 n (Patient) 47 23 47 30 47 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCR only UO only AUC 0.48 0.54 0.48 0.48 0.63 0.50 0.32 0.50 0.34 SE 0.067 0.097 0.073 0.064 0.076 0.066 0.078 0.11 0.090 P 0.79 0.70 0.75 0.81 0.076 0.96 0.024 0.98 0.081 nCohort 1 53 133 54 53 133 54 53 133 54 nCohort 2 29 10 23 34 17 30 18 8 13 Cutoff 1 17.6 26.2 14.8 17.9 31.5 17.6 12.2 13.9 10.7 Sens 1 72% 70% 74% 71% 71% 70% 72% 75% 77% Spec 1 26% 50% 15% 26% 56% 28%  8% 20% 11% Cutoff 2 11.0 13.1 10.7 15.6 17.9 13.4 9.82 11.5 9.82 Sens 2 83% 80% 83% 82% 82% 80% 83% 88% 85% Spec 2  8% 16% 11% 11% 34% 13%  8% 14%  9% Cutoff 3 8.88 10.7 6.26 6.68 9.95 6.68 8.88 8.88 8.88 Sens 3 93% 90% 91% 91% 94% 90% 94% 100%  92% Spec 3  8% 14%  2%  2% 11%  2%  8% 11%  9% Cutoff 4 46.9 43.7 43.7 46.9 43.7 43.7 46.9 43.7 43.7 Sens 4 34% 30% 30% 32% 53% 37% 22% 38% 15% Spec 4 72% 71% 70% 72% 71% 70% 72% 71% 70% Cutoff 5 56.7 60.9 54.5 56.7 60.9 54.5 56.7 60.9 54.5 Sens 5 31% 30% 26% 26% 41% 23% 22% 25% 15% Spec 5 81% 80% 81% 81% 80% 81% 81% 80% 81% Cutoff 6 117 95.2 94.9 117 95.2 94.9 117 95.2 94.9 Sens 6 10% 20%  9%  9% 18% 10%  6% 12%  0% Spec 6 91% 90% 91% 91% 90% 91% 91% 90% 91% OR Quart 2 0.44 0.30 0.50 1.0 0.63 1.0 0.21 1.0 1.0 p Value 0.23 0.31 0.34 1.0 0.62 1.0 0.18 0.98 1.0 95% CI of 0.12 0.030 0.12 0.30 0.099 0.29 0.021 0.14 0.12 OR Quart 2 1.7 3.1 2.1 3.3 4.0 3.5 2.1 7.7 8.1 OR Quart 3 0.67 0.97 0.66 0.67 1.8 0.65 1.3 0.50 2.3 p Value 0.53 0.97 0.56 0.53 0.46 0.51 0.70 0.58 0.38 95% CI of 0.19 0.18 0.17 0.20 0.39 0.18 0.30 0.043 0.36 OR Quart 3 2.3 5.2 2.6 2.3 8.0 2.4 6.1 5.8 15 OR Quart 4 0.89 0.97 1.1 1.1 2.6 1.0 3.1 1.6 3.4 p Value 0.85 0.97 0.90 0.90 0.20 1.0 0.13 0.62 0.19 95% CI of 0.26 0.18 0.29 0.32 0.61 0.29 0.72 0.25 0.56 OR Quart 4 3.1 5.2 4.0 3.6 11 3.5 13 10 21 Coagulation factor VII 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 312 313 312 280 312 290 Average 339 323 339 283 339 310 Stdev 159 179 159 165 159 165 p (t-test) 0.52 0.017 0.37 Min 2.08 22.9 2.08 12.2 2.08 66.4 Max 743 759 743 717 743 685 n (Samp) 262 51 262 56 262 26 n (Patient) 110 51 110 56 110 26 sCr only Median 298 336 298 324 298 418 Average 313 356 313 361 313 391 Stdev 164 187 164 219 164 206 p (t-test) 0.28 0.20 0.095 Min 2.08 108 2.08 66.2 2.08 62.4 Max 822 759 822 779 822 685 n (Samp) 466 18 466 21 466 13 n (Patient) 180 18 180 21 180 13 UO only Median 310 296 310 262 310 261 Average 335 304 335 256 335 271 Stdev 160 174 160 144 160 119 p (t-test) 0.21 0.0012 0.063 Min 16.0 22.9 16.0 12.2 16.0 66.4 Max 1020 722 1020 574 1020 488 n (Samp) 221 50 221 52 221 23 n (Patient) 91 50 91 52 91 23 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCR only UO only AUC 0.47 0.56 0.45 0.40 0.55 0.36 0.44 0.62 0.40 SE 0.045 0.071 0.046 0.043 0.066 0.045 0.061 0.084 0.065 p 0.43 0.40 0.23 0.017 0.45 0.0022 0.36 0.17 0.11 nCohort 1 262 466 221 262 466 221 262 466 221 nCohort 2 51 18 50 56 21 52 26 13 23 Cutoff 1 193 225 176 165 190 156 220 187 220 Sens 1 71% 72% 72% 71% 71% 71% 73% 77% 74% Spec 1 18% 35% 14% 12% 27% 11% 26% 26% 27% Cutoff 2 140 182 138 138 138 100 134 137 129 Sens 2 80% 83% 80% 80% 81% 81% 81% 85% 83% Spec 2  8% 24%  8%  8% 14%  4%  7% 13%  6% Cutoff 3 104 126 77.8 80.6 108 76.2 116 124 116 Sens 3 90% 94% 90% 91% 90% 90% 92% 92% 91% Spec 3  4% 12%  3%  3%  8%  3%  5% 11%  5% Cutoff 4 411 394 393 411 394 393 411 394 393 Sens 4 29% 39% 34% 23% 43% 21% 27% 62% 17% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 481 459 479 481 459 479 481 459 479 Sens 5 22% 28% 18% 12% 38%  8% 15% 38%  4% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 571 535 550 571 535 550 571 535 550 Sens 6 10% 22% 10%  5% 24%  2%  8% 31%  0% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 1.2 1.0 1.2 0.91 0.48 1.3 1.2 0.32 2.1 p Value 0.64 1.0 0.65 0.84 0.31 0.60 0.75 0.33 0.31 95% CI of 0.53 0.24 0.51 0.36 0.12 0.50 0.35 0.033 0.50 OR Quart 2 2.8 4.1 3.0 2.3 2.0 3.3 4.2 3.2 8.9 OR Quart 3 0.64 1.0 0.69 1.1 0.48 1.1 1.7 1.3 2.9 p Value 0.36 1.0 0.46 0.82 0.31 0.78 0.39 0.71 0.13 95% CI of 0.25 0.24 0.26 0.46 0.12 0.44 0.52 0.29 0.74 OR Quart 3 1.7 4.1 1.8 2.7 2.0 3.0 5.4 6.1 12 OR Quart 4 1.6 1.5 1.9 2.6 1.5 3.2 1.4 1.7 2.1 p Value 0.29 0.52 0.13 0.020 0.44 0.0086 0.55 0.48 0.31 95% CI of 0.69 0.42 0.82 1.2 0.53 1.3 0.44 0.39 0.50 OR Quart 4 3.5 5.5 4.4 5.7 4.4 7.6 4.8 7.2 8.9 Insulin-like growth factor-binding protein 7 0 hr prior to 24 hr prior to 48 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 63.1 74.8 63.1 82.4 63.1 75.2 Average 68.7 77.4 68.7 94.1 68.7 74.1 Stdev 34.7 31.0 34.7 68.0 34.7 20.5 p (t-test) 0.19 0.0063 0.46 Min 18.6 35.4 18.6 30.8 18.6 28.3 Max 250 185 250 437 250 114 n (Samp) 81 37 81 45 81 26 n (Patient) 74 37 74 45 74 26 sCr only Median 67.7 75.4 67.7 92.0 67.7 74.4 Average 75.5 78.1 75.5 113 75.5 74.4 Stdev 41.1 39.2 41.1 59.9 41.1 25.4 p (t-test) 0.83 0.0017 0.94 Min 18.6 35.4 18.6 30.8 18.6 28.3 Max 437 185 437 233 437 116 n (Samp) 197 12 197 14 197 9 n (Patient) 131 12 131 14 131 9 UO only Median 69.3 76.7 69.3 81.8 69.3 77.9 Average 74.2 80.9 74.2 92.0 74.2 82.1 Stdev 33.6 32.7 33.6 65.1 33.6 30.6 p (t-test) 0.36 0.051 0.33 Min 27.8 39.1 27.8 36.0 27.8 39.8 Max 250 189 250 437 250 185 n (Samp) 77 29 77 43 77 21 n (Patient) 64 29 64 43 64 21 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCR only UO only AUC 0.61 0.52 0.58 0.65 0.72 0.60 0.62 0.54 0.61 SE 0.057 0.087 0.064 0.052 0.079 0.055 0.066 0.10 0.072 P 0.064 0.83 0.23 0.0039 0.0049 0.081 0.071 0.71 0.14 nCohort 1 81 197 77 81 197 77 81 197 77 nCohort 2 37 12 29 45 14 43 26 9 21 Cutoff 1 56.1 68.2 56.5 56.3 82.4 53.8 58.3 69.0 62.3 Sens 1 70% 75% 72% 71% 71% 72% 73% 78% 71% Spec 1 44% 51% 36% 44% 66% 31% 47% 51% 42% Cutoff 2 53.1 39.8 53.3 53.1 70.5 52.5 56.1 49.8 58.1 Sens 2 81% 83% 83% 80% 86% 81% 81% 89% 81% Spec 2 40% 10% 31% 40% 53% 27% 44% 22% 39% Cutoff 3 39.4 36.7 47.5 42.8 56.5 42.8 49.8 27.8 53.3 Sens 3 92% 92% 93% 91% 93% 91% 92% 100%  90% Spec 3 16%  6% 17% 20% 38% 12% 32%  2% 31% Cutoff 4 77.3 85.8 84.2 77.3 85.8 84.2 77.3 85.8 84.2 Sens 4 46% 17% 38% 53% 64% 49% 42% 22% 38% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 85.8 96.3 87.7 85.8 96.3 87.7 85.8 96.3 87.7 Sens 5 30% 17% 31% 47% 43% 44% 27% 22% 38% Spec 5 80% 80% 81% 80% 80% 81% 80% 80% 81% Cutoff 6 107 116 114 107 116 114 107 116 114 Sens 6 11%  8% 14% 18% 29% 19%  4% 11% 10% Spec 6 90% 90% 91% 90% 90% 91% 90% 90% 91% OR Quart 2 1.4 0.32 3.2 2.5 0.98 1.2 4.2 0 7.3 p Value 0.59 0.33 0.082 0.12 0.99 0.78 0.094 na 0.078 95% CI of 0.42 0.032 0.86 0.80 0.060 0.39 0.78 na 0.80 OR Quart 2 4.7 3.2 12 7.8 16 3.5 23 na 66 OR Quart 3 2.7 2.1 1.6 1.4 5.3 0.71 6.0 2.7 7.7 p Value 0.094 0.30 0.48 0.54 0.13 0.56 0.033 0.26 0.070 95% CI of 0.85 0.50 0.41 0.44 0.60 0.22 1.2 0.49 0.85 OR Quart 3 8.7 9.0 6.7 4.8 47 2.2 31 14 70 OR Quart 4 2.2 0.64 2.8 6.1 7.8 3.1 5.1 0.98 11 p Value 0.18 0.63 0.14 0.0018 0.060 0.040 0.056 0.98 0.032 95% CI of 0.69 0.10 0.73 2.0 0.92 1.1 0.96 0.13 1.2 OR Quart 4 7.1 4.0 10 19 65 8.8 27 7.2 95

TABLE 6 Comparison of marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R) and in EDTA samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage I or F in Cohort 2. Cancer Antigen 19-9 24 hr prior to 48 hr prior to 0 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.228 0.629 0.228 0.536 0.228 0.489 Average 0.628 1.13 0.628 0.885 0.628 0.805 Stdev 3.00 1.07 3.00 1.17 3.00 1.05 p(t-test) 0.66 0.70 0.81 Min 1.00E−9 0.231 1.00E−9 1.00E−9 1.00E−9 0.0291 Max 41.6 2.77 41.6 5.26 41.6 3.84 n (Samp) 197 7 197 21 197 16 n (Patient) 131 7 131 21 131 16 UO only Median nd nd 0.244 0.467 0.244 0.568 Average nd nd 0.695 0.831 0.695 0.776 Stdev nd nd 3.19 1.21 3.19 1.04 p (t-test) nd nd 0.86 0.93 Min nd nd 1.00E−9 1.00E−9 1.00E−9 0.0291 Max nd nd 41.6 5.26 41.6 3.84 n (Samp) nd nd 173 18 173 13 n (Patient) nd nd 111 18 111 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.79 nd nd 0.71 nd 0.66 0.63 nd 0.62 SE 0.10 nd nd 0.066 nd 0.073 0.077 nd 0.086 p 0.0047 nd nd 0.0013 nd 0.031 0.081 nd 0.15 nCohort 1 197 nd nd 197 nd 173 197 nd 173 nCohort 2 7 nd nd 21 nd 18 16 nd 13 Cutoff 1 0.401 nd nd 0.259 nd 0.257 0.204 nd 0.204 Sens 1 71% nd nd 71% nd 72% 75% nd 77% Spec 1 71% nd nd 55% nd 53% 44% nd 41% Cutoff 2 0.288 nd nd 0.250 nd 0.228 0.134 nd 0.0842 Sens 2 86% nd nd 81% nd 83% 81% nd 85% Spec 2 61% nd nd 55% nd 50% 30% nd 22% Cutoff 3 0.228 nd nd 0.174 nd 0.134 0.0783 nd 0.0783 Sens 3 100%  nd nd 90% nd 94% 94% nd 92% Spec 3 52% nd nd 36% nd 29% 20% nd 18% Cutoff 4 0.361 nd nd 0.361 nd 0.456 0.361 nd 0.456 Sens 4 71% nd nd 67% nd 50% 56% nd 54% Spec 4 70% nd nd 70% nd 71% 70% nd 71% Cutoff 5 0.590 nd nd 0.590 nd 0.633 0.590 nd 0.633 Sens 5 57% nd nd 43% nd 33% 38% nd 23% Spec 5 80% nd nd 80% nd 80% 80% nd 80% Cutoff 6 0.980 nd nd 0.980 nd 1.32 0.980 nd 1.32 Sens 6 43% nd nd 24% nd 11% 19% nd 15% Spec 6 90% nd nd 90% nd 90% 90% nd 90% OR Quart 2 >0 nd nd 3.1 nd 3.1 0.65 nd 0.31 p Value <na nd nd 0.34 nd 0.34 0.65 nd 0.32 95% CI of >na nd nd 0.31 nd 0.31 0.10 nd 0.031 OR Quart 2 na nd nd 30 nd 31 4.1 nd 3.1 OR Quart 3 >3.2 nd nd 6.6 nd 7.9 1.0 nd 1.0 p Value <0.32 nd nd 0.085 nd 0.059 1.0 nd 1.0 95% CI of >0.32 nd nd 0.77 nd 0.93 0.19 nd 0.19 OR Quart 3 na nd nd 57 nd 67 5.2 nd 5.2 OR Quart 4 >4.3 nd nd 13 nd 7.9 2.9 nd 2.1 p Value <0.20 nd nd 0.015 nd 0.059 0.13 nd 0.32 95% CI of >0.47 nd nd 1.6 nd 0.93 0.72 nd 0.49 OR Quart 4 na nd nd 110 nd 67 12 nd 8.9 C-C motif chemokine 13 24 hr prior to 48 hr prior to 0 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 21.0 21.8 21.0 1.00E−9 21.0 44.5 Average 66.3 56.7 66.3 29.4 66.3 90.1 Stdev 235 86.8 235 61.3 235 140 p (t-test) 0.92 0.48 0.72 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2520 238 2520 279 2520 484 n (Samp) 130 7 130 21 130 13 n (Patient) 102 7 102 21 102 13 UO only Median nd nd 21.0 1.00E−9 21.0 44.5 Average nd nd 70.0 16.9 70.0 74.5 Stdev nd nd 253 20.5 253 140 p (t-test) nd nd 0.34 0.95 Min nd nd 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max nd nd 2520 44.5 2520 484 n (Samp) nd nd 112 21 112 11 n (Patient) nd nd 87 21 87 11 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.51 nd nd 0.40 nd 0.39 0.59 nd 0.54 SE 0.11 nd nd 0.070 nd 0.070 0.087 nd 0.093 p 0.91 nd nd 0.14 nd 0.11 0.28 nd 0.70 nCohort 1 130 nd nd 130 nd 112 130 nd 112 nCohort 2 7 nd nd 21 nd 21 13 nd 11 Cutoff 1 0 nd nd 0 nd 0 0 nd 0 Sens 1 100%  nd nd 100%  nd 100%  100%  nd 100%  Spec 1  0% nd nd  0% nd  0%  0% nd  0% Cutoff 2 0 nd nd 0 nd 0 0 nd 0 Sens 2 100%  nd nd 100%  nd 100%  100%  nd 100%  Spec 2  0% nd nd  0% nd  0%  0% nd  0% Cutoff 3 0 nd nd 0 nd 0 0 nd 0 Sens 3 100%  nd nd 100%  nd 100%  100%  nd 100%  Spec 3  0% nd nd  0% nd  0%  0% nd  0% Cutoff 4 56.0 nd nd 56.0 nd 56.0 56.0 nd 56.0 Sens 4 29% nd nd 10% nd  0% 38% nd 36% Spec 4 73% nd nd 73% nd 72% 73% nd 72% Cutoff 5 72.2 nd nd 72.2 nd 72.2 72.2 nd 72.2 Sens 5 29% nd nd  5% nd  0% 31% nd 27% Spec 5 82% nd nd 82% nd 81% 82% nd 81% Cutoff 6 111 nd nd 111 nd 111 111 nd 111 Sens 6 14% nd nd  5% nd  0% 15% nd  9% Spec 6 90% nd nd 90% nd 90% 90% nd 90% OR Quart 2 >3.3 nd nd 4.1 nd >13 >4.4 nd >5.8 p Value <0.31 nd nd 0.094 nd <0.019 <0.20 nd <0.12 95% CI of >0.32 nd nd 0.79 nd >1.5 >0.46 nd >0.63 OR Quart 2 na nd nd 21 nd na na nd na OR Quart 3 >2.1 nd nd 8.3 nd >0 >4.4 nd >2.1 p Value <0.55 nd nd 0.0086 nd <na <0.20 nd <0.56 95% CI of >0.18 nd nd 1.7 nd >na >0.46 nd >0.18 OR Quart 3 na nd nd 40 nd na na nd na OR Quart 4 >2.1 nd nd 0 nd >19 >5.6 nd >4.4 p Value <0.56 nd nd na nd <0.0059 <0.12 nd <0.19 95% CI of >0.18 nd nd na nd >2.4 >0.62 nd >0.47 OR Quart 4 na nd nd na nd na na nd na C—X—C motif chemokine 6 24 hr prior to 48 hr prior to 0 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 27.2 43.7 27.2 29.1 27.2 32.9 Average 42.6 88.3 42.6 49.9 42.6 66.7 Stdev 42.3 86.5 42.3 55.1 42.3 83.1 p (t-test) 0.0100 0.48 0.080 Min 3.49 8.06 3.49 9.69 3.49 9.55 Max 244 258 244 244 244 311 n (Samp) 131 7 131 21 131 13 n (Patient) 103 7 103 21 103 13 UO only Median nd nd 25.5 29.1 25.5 24.0 Average nd nd 40.5 44.7 40.5 61.1 Stdev nd nd 42.9 50.5 42.9 87.4 p (t-test) nd nd 0.69 0.18 Min nd nd 3.49 8.06 3.49 9.69 Max nd nd 244 244 244 311 n (Samp) nd nd 113 21 113 11 n (Patient) nd nd 88 21 88 11 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.68 nd nd 0.54 nd 0.55 0.59 nd 0.57 SE 0.11 nd nd 0.069 nd 0.070 0.087 nd 0.094 p 0.11 nd nd 0.55 nd 0.46 0.28 nd 0.48 nCohort 1 131 nd nd 131 nd 113 131 nd 113 nCohort 2 7 nd nd 21 nd 21 13 nd 11 Cutoff 1 38.9 nd nd 17.6 nd 17.6 23.3 nd 23.3 Sens 1 71% nd nd 71% nd 71% 77% nd 73% Spec 1 62% nd nd 34% nd 36% 44% nd 47% Cutoff 2 31.8 nd nd 15.8 nd 15.8 17.6 nd 17.6 Sens 2 86% nd nd 81% nd 81% 85% nd 82% Spec 2 56% nd nd 25% nd 29% 34% nd 36% Cutoff 3 6.68 nd nd 13.9 nd 13.9 16.7 nd 16.7 Sens 3 100%  nd nd 90% nd 90% 92% nd 91% Spec 3  5% nd nd 19% nd 24% 31% nd 34% Cutoff 4 46.0 nd nd 46.0 nd 43.7 46.0 nd 43.7 Sens 4 43% nd nd 33% nd 33% 38% nd 27% Spec 4 70% nd nd 70% nd 72% 70% nd 72% Cutoff 5 60.9 nd nd 60.9 nd 54.2 60.9 nd 54.2 Sens 5 43% nd nd 29% nd 24% 31% nd 27% Spec 5 80% nd nd 80% nd 81% 80% nd 81% Cutoff 6 93.3 nd nd 93.3 nd 89.9 93.3 nd 89.9 Sens 6 43% nd nd 10% nd  5% 23% nd 18% Spec 6 90% nd nd 90% nd 90% 90% nd 90% OR Quart 2 0 nd nd 1.6 nd 2.6 5.6 nd 5.8 p Value na nd nd 0.50 nd 0.20 0.12 nd 0.12 95% CI of na nd nd 0.41 nd 0.61 0.62 nd 0.63 OR Quart 2 na nd nd 6.2 nd 11 51 nd 53 OR Quart 3 3.2 nd nd 1.3 nd 1.8 3.2 nd 2.1 p Value 0.33 nd nd 0.72 nd 0.46 0.33 nd 0.56 95% CI of 0.32 nd nd 0.32 nd 0.39 0.31 nd 0.18 OR Quart 3 32 nd nd 5.2 nd 8.2 32 nd 24 OR Quart 4 3.1 nd nd 1.6 nd 2.1 4.4 nd 3.2 p Value 0.34 nd nd 0.50 nd 0.31 0.20 nd 0.32 95% CI of 0.31 nd nd 0.41 nd 0.49 0.46 nd 0.32 OR Quart 4 31 nd nd 6.2 nd 9.4 41 nd 33 Coagulation factor VII 24 hr prior to 48 hr prior to 0 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 310 281 310 235 310 221 Average 336 290 336 259 336 277 Stdev 172 149 172 173 172 188 p (t-test) 0.19 0.014 0.17 Min 2.08 51.4 2.08 22.9 2.08 12.2 Max 1020 549 1020 626 1020 616 n (Samp) 437 26 437 33 437 17 n (Patient) 174 26 174 33 174 17 sCr only Median 303 188 303 251 303 189 Average 323 244 323 296 323 317 Stdev 174 189 174 235 174 219 p (t-test) 0.27 0.65 0.93 Min 2.08 77.8 2.08 66.2 2.08 110 Max 1020 605 1020 779 1020 622 n (Samp) 535 6 535 9 535 7 n (Patient) 207 6 207 9 207 7 UO only Median 302 286 302 235 302 193 Average 321 310 321 253 321 247 Stdev 163 155 163 168 163 172 p (t-test) 0.75 0.026 0.070 Min 16.0 51.4 16.0 22.9 16.0 12.2 Max 1020 611 1020 626 1020 616 n (Samp) 363 26 363 31 363 17 n (Patient) 141 26 141 31 141 17 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.43 0.34 0.49 0.37 0.42 0.38 0.40 0.46 0.36 SE 0.060 0.12 0.059 0.054 0.10 0.056 0.074 0.11 0.074 p 0.28 0.19 0.87 0.017 0.42 0.028 0.16 0.71 0.064 nCohort 1 437 535 363 437 535 363 437 535 363 nCohort 2 26 6 26 33 9 31 17 7 17 Cutoff 1 173 126 173 126 130 126 127 166 126 Sens 1 73% 83% 73% 73% 78% 74% 71% 71% 76% Spec 1 17% 11% 18%  9% 12% 10%  9% 20% 10% Cutoff 2 156 126 163 79.5 74.8 99.7 116 156 116 Sens 2 81% 83% 81% 82% 89% 81% 82% 86% 82% Spec 2 14% 11% 16%  3%  5%  6%  6% 17%  7% Cutoff 3 76.2 76.2 136 56.6 65.3 64.8 66.2 108 66.2 Sens 3 92% 100%  92% 91% 100%  90% 94% 100%  94% Spec 3  3%  5% 10%  2%  4%  2%  2%  8%  2% Cutoff 4 405 403 387 405 403 387 405 403 387 Sens 4 27% 17% 38% 21% 22% 23% 29% 29% 24% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70% Cutoff 5 481 469 449 481 469 449 481 469 449 Sens 5  8% 17% 27% 12% 22% 10% 12% 29% 18% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80% Cutoff 6 573 564 536 573 564 536 573 564 536 Sens 6  0% 17%  8%  6% 11% 10% 12% 29%  6% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90% OR Quart 2 0.56 0 0.48 1.7 0.50 1.0 0.75 0.50 0.49 p Value 0.36 na 0.25 0.39 0.57 0.99 0.71 0.57 0.42 95% CI of 0.16 na 0.14 0.53 0.044 0.31 0.16 0.045 0.087 OR Quart 2 2.0 na 1.7 5.2 5.5 3.2 3.4 5.6 2.7 OR Quart 3 0.70 2.0 0.61 1.0 1.5 0.82 0.49 0.50 0.49 p Value 0.56 0.57 0.40 1.0 0.65 0.76 0.42 0.57 0.42 95% CI of 0.22 0.18 0.19 0.28 0.25 0.24 0.088 0.044 0.087 OR Quart 3 2.3 23 1.9 3.5 9.2 2.8 2.7 5.5 2.7 OR Quart 4 1.5 3.1 1.2 3.3 1.5 2.6 2.1 1.5 2.4 p Value 0.44 0.33 0.78 0.025 0.65 0.063 0.24 0.65 0.16 95% CI of 0.54 0.32 0.42 1.2 0.25 0.95 0.61 0.25 0.71 OR Quart 4 4.0 30 3.1 9.5 9.2 7.0 7.2 9.3 8.0 Insulin-like growth factor-binding protein 7 24 hr prior to 48 hr prior to 0 hr prior to AKI stage AKI stage AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 68.2 77.5 68.2 93.6 68.2 75.4 Average 73.4 93.2 73.4 112 73.4 84.5 Stdev 33.2 49.8 33.2 89.8 33.2 34.5 p (t-test) 0.13 7.1E−5 0.20 Min 18.6 37.5 18.6 43.7 18.6 50.1 Max 250 189 250 437 250 176 n (Samp) 197 7 197 21 197 16 n (Patient) 131 7 131 21 131 16 UO only Median nd nd 73.5 97.8 73.5 88.5 Average nd nd 76.5 117 76.5 92.9 Stdev nd nd 33.2 92.8 33.2 38.7 p (t-test) nd nd 1.7E−4 0.091 Min nd nd 27.8 43.7 27.8 54.2 Max nd nd 250 437 250 176 n (Samp) nd nd 173 18 173 13 n (Patient) nd nd 111 18 111 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.63 nd nd 0.66 nd 0.65 0.61 nd 0.65 SE 0.12 nd nd 0.068 nd 0.073 0.077 nd 0.085 p 0.28 nd nd 0.021 nd 0.036 0.14 nd 0.084 nCohort 1 197 nd nd 197 nd 173 197 nd 173 nCohort 2 7 nd nd 21 nd 18 16 nd 13 Cutoff 1 74.2 nd nd 57.2 nd 57.2 58.1 nd 58.1 Sens 1 71% nd nd 71% nd 72% 75% nd 77% Spec 1 56% nd nd 40% nd 36% 40% nd 36% Cutoff 2 57.2 nd nd 53.5 nd 52.0 56.1 nd 56.1 Sens 2 86% nd nd 81% nd 83% 81% nd 85% Spec 2 40% nd nd 34% nd 22% 37% nd 33% Cutoff 3 36.7 nd nd 49.8 nd 49.5 53.9 nd 55.2 Sens 3 100%  nd nd 90% nd 94% 94% nd 92% Spec 3  8% nd nd 24% nd 18% 34% nd 32% Cutoff 4 84.3 nd nd 84.3 nd 85.9 84.3 nd 85.9 Sens 4 43% nd nd 52% nd 61% 44% nd 54% Spec 4 70% nd nd 70% nd 71% 70% nd 71% Cutoff 5 91.7 nd nd 91.7 nd 97.1 91.7 nd 97.1 Sens 5 43% nd nd 52% nd 50% 31% nd 38% Spec 5 80% nd nd 80% nd 80% 80% nd 80% Cutoff 6 114 nd nd 114 nd 114 114 nd 114 Sens 6 29% nd nd 33% nd 39% 19% nd 31% Spec 6 90% nd nd 90% nd 90% 90% nd 90% OR Quart 2 1.0 nd nd 1.7 nd 0.72 5.4 nd >5.5 p Value 1.0 nd nd 0.48 nd 0.67 0.13 nd <0.13 95% CI of 0.061 nd nd 0.39 nd 0.15 0.61 nd >0.61 OR Quart 2 16 nd nd 7.5 nd 3.4 48 nd na OR Quart 3 2.0 nd nd 0.65 nd 0 4.2 nd >2.1 p Value 0.57 nd nd 0.65 nd na 0.20 nd <0.55 95% CI of 0.18 nd nd 0.10 nd na 0.46 nd >0.18 OR Quart 3 23 nd nd 4.1 nd na 39 nd na OR Quart 4 3.1 nd nd 4.2 nd 3.2 6.5 nd >6.7 p Value 0.33 nd nd 0.034 nd 0.063 0.088 nd <0.083 95% CI of 0.31 nd nd 1.1 nd 0.94 0.75 nd >0.78 OR Quart 4 31 nd nd 16 nd 11 56 nd na

TABLE 7 Comparison of marker levels in EDTA samples collected within 12 hours of reaching stage R from Cohort 1 (patients that reached, but did not progress beyond, RIFLE stage R) and from Cohort 2 (patients that reached RIFLE stage I or F). Coagulation factor VII sCr or UO sCr only Cohort Cohort Cohort Cohort UO only 1 2 1 2 Cohort 1 Cohort 2 Median 313 250 240 333 324 279 Average 335 258 333 282 325 268 Stdev 191 169 213 142 182 169 p (t-test) 0.10 0.57 0.28 Min 35.7 22.9 65.3 75.6 35.7 22.9 Max 809 616 759 453 809 616 n (Samp) 55 22 18 7 46 16 n (Patient) 55 22 18 7 46 16 At Enrollment sCr or UO sCr only UO only AUC 0.38 0.46 0.41 SE 0.073 0.13 0.085 p 0.100 0.76 0.28 nCohort 1 55 18 46 nCohort 2 22 7 16 Cutoff 1 137 245 137 Sens 1 73% 71% 81% Spec 1 15% 56% 17% Cutoff 2 95.4 75.6 137 Sens 2 82% 86% 81% Spec 2  5%  6% 17% Cutoff 3 51.2 65.3 35.7 Sens 3 91% 100%  94% Spec 3  2%  6%  2% Cutoff 4 446 415 446 Sens 4 14% 14% 12% Spec 4 71% 72% 72% Cutoff 5 484 536 483 Sens 5 14%  0% 12% Spec 5 80% 83% 80% Cutoff 6 598 737 536 Sens 6  5%  0% 12% Spec 6 91% 94% 91% OR Quart 2 3.3 12 3.5 p Value 0.13 0.073 0.18 95% CI of 0.71 0.80 0.56 OR Quart 2 15 180 22 OR Quart 3 1.5 0 2.3 p Value 0.62 na 0.37 95% CI of 0.29 na 0.36 OR Quart 3 7.9 na 15 OR Quart 4 4.1 3.0 3.5 p Value 0.069 0.43 0.18 95% CI of 0.89 0.20 0.56 OR Quart 4 19 45 22

TABLE 8 Comparison of the maximum marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and the maximum values in EDTA samples collected from subjects between enrollment and 0, 24 hours, and 48 hours prior to reaching stage F in Cohort 2. Cancer Antigen 19-9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 0.204 0.652 0.204 0.601 nd nd Average 0.339 1.21 0.339 1.16 nd nd Stdev 0.668 1.66 0.668 1.67 nd nd p (t-test) 0.0046 0.0077 nd nd Min 1.00E−9 0.145 1.00E−9 0.145 nd nd Max 5.30 5.26 5.30 5.26 nd nd n (Samp) 74 8 74 8 nd nd n (Patient) 74 8 74 8 nd nd UO only Median 0.258 0.588 0.258 0.588 nd nd Average 0.472 1.33 0.472 1.33 nd nd Stdev 0.791 1.95 0.791 1.95 nd nd p (t-test) 0.034 0.034 nd nd Min 1.00E−9 0.145 1.00E−9 0.145 nd nd Max 5.30 5.26 5.30 5.26 nd nd n (Samp) 64 6 64 6 nd nd n (Patient) 64 6 64 6 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.85 nd 0.74 0.84 nd 0.74 nd nd nd SE 0.088 nd 0.12 0.090 nd 0.12 nd nd nd p 7.4E−5 nd 0.045 2.0E−4 nd 0.045 nd nd nd nCohort 1 74 nd 64 74 nd 64 nd nd nd nCohort 2 8 nd 6 8 nd 6 nd nd nd Cutoff 1 0.546 nd 0.358 0.546 nd 0.358 nd nd nd Sens 1 75% nd 83% 75% nd 83% nd nd nd Spec 1 88% nd 69% 88% nd 69% nd nd nd Cutoff 2 0.358 nd 0.358 0.358 nd 0.358 nd nd nd Sens 2 88% nd 83% 88% nd 83% nd nd nd Spec 2 80% nd 69% 80% nd 69% nd nd nd Cutoff 3 0.124 nd 0.134 0.124 nd 0.134 nd nd nd Sens 3 100%  nd 100%  100%  nd 100%  nd nd nd Spec 3 34% nd 28% 34% nd 28% nd nd nd Cutoff 4 0.311 nd 0.401 0.311 nd 0.401 nd nd nd Sens 4 88% nd 67% 88% nd 67% nd nd nd Spec 4 70% nd 70% 70% nd 70% nd nd nd Cutoff 5 0.401 nd 0.629 0.401 nd 0.629 nd nd nd Sens 5 75% nd 33% 75% nd 33% nd nd nd Spec 5 81% nd 81% 81% nd 81% nd nd nd Cutoff 6 0.629 nd 0.944 0.629 nd 0.944 nd nd nd Sens 6 50% nd 33% 38% nd 33% nd nd nd Spec 6 91% nd 91% 91% nd 91% nd nd nd OR Quart 2 >1.0 nd >1.0 >1.0 nd >1.0 nd nd nd p Value <1.0 nd <1.0 <1.0 nd <1.0 nd nd nd 95% CI of >0.058 nd >0.058 >0.058 nd >0.058 nd nd nd OR Quart 2 na nd na na nd na nd nd nd OR Quart 3 >1.1 nd >1.1 >1.1 nd >1.1 nd nd nd p Value <0.97 nd <0.97 <0.97 nd <0.97 nd nd nd 95% CI of >0.061 nd >0.061 >0.061 nd >0.061 nd nd nd OR Quart 3 na nd na na nd na nd nd nd OR Quart 4 >8.0 nd >4.9 >8.0 nd >4.9 nd nd nd p Value <0.066 nd <0.18 <0.066 nd <0.18 nd nd nd 95% CI of >0.87 nd >0.49 >0.87 nd >0.49 nd nd nd OR Quart 4 na nd na na nd na nd nd nd C-C motif chemokine 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 21.0 42.6 21.0 42.6 21.0 42.6 Average 104 90.3 104 90.3 104 42.9 Stdev 371 199 371 199 371 32.6 p (t-test) 0.90 0.90 0.69 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2520 713 2520 713 2520 96.3 n (Samp) 50 12 50 12 50 6 n (Patient) 50 12 50 12 50 6 sCr only Median 21.0 1.00E−9 21.0 1.00E−9 nd nd Average 72.5 20.5 72.5 20.5 nd nd Stdev 268 32.0 268 32.0 nd nd p (t-test) 0.64 0.64 nd nd Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 nd nd Max 2520 68.2 2520 68.2 nd nd n (Samp) 100 6 100 6 nd nd n (Patient) 100 6 100 6 nd nd UO only Median 21.0 44.5 21.0 44.5 21.0 42.6 Average 115 127 115 127 115 42.9 Stdev 387 239 387 239 387 32.6 p (t-test) 0.93 0.93 0.65 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 2520 713 2520 713 2520 96.3 n (Samp) 46 8 46 8 46 6 n (Patient) 46 8 46 8 46 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.54 0.40 0.63 0.54 0.40 0.63 0.58 nd 0.58 SE 0.095 0.13 0.11 0.095 0.13 0.11 0.13 nd 0.13 p 0.69 0.41 0.25 0.69 0.41 0.25 0.53 nd 0.56 nCohort 1 50 100 46 50 100 46 50 nd 46 nCohort 2 12 6 8 12 6 8 6 nd 6 Cutoff 1 0 0 38.0 0 0 38.0 7.19 nd 7.19 Sens 1 100%  100%  75% 100%  100%  75% 83% nd 83% Spec 1  0%  0% 61%  0%  0% 61% 44% nd 43% Cutoff 2 0 0 7.19 0 0 7.19 7.19 nd 7.19 Sens 2 100%  100%  88% 100%  100%  88% 83% nd 83% Spec 2  0%  0% 43%  0%  0% 43% 44% nd 43% Cutoff 3 0 0 0 0 0 0 0 nd 0 Sens 3 100%  100%  100%  100%  100%  100%  100%  nd 100%  Spec 3  0%  0%  0%  0%  0%  0%  0% nd  0% Cutoff 4 56.0 44.5 59.5 56.0 44.5 59.5 56.0 nd 59.5 Sens 4 25% 33% 25% 25% 33% 25% 17% nd 17% Spec 4 70% 70% 72% 70% 70% 72% 70% nd 72% Cutoff 5 72.2 69.2 69.2 72.2 69.2 69.2 72.2 nd 69.2 Sens 5 17%  0% 25% 17%  0% 25% 17% nd 17% Spec 5 80% 81% 80% 80% 81% 80% 80% nd 80% Cutoff 6 105 96.3 105 105 96.3 105 105 nd 105 Sens 6  8%  0% 12%  8%  0% 12%  0% nd  0% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 0.18 1.0 0.92 0.18 1.0 0.92 1.0 nd 1.0 p Value 0.15 0.98 0.96 0.15 0.98 0.96 1.0 nd 1.0 95% CI of 0.018 0.062 0.052 0.018 0.062 0.052 0.056 nd 0.056 OR Quart 2 1.9 18 16 1.9 18 16 18 nd 18 OR Quart 3 1.0 4.5 5.3 1.0 4.5 5.3 3.5 nd 3.6 p Value 1.0 0.19 0.16 1.0 0.19 0.16 0.30 nd 0.30 95% CI of 0.20 0.47 0.51 0.20 0.47 0.51 0.32 nd 0.32 OR Quart 3 5.0 43 56 5.0 43 56 39 nd 40 OR Quart 4 0.63 0 2.0 0.63 0 2.0 1.0 nd 1.0 p Value 0.60 na 0.59 0.60 na 0.59 1.0 nd 1.0 95% CI of 0.12 na 0.16 0.12 na 0.16 0.056 nd 0.056 OR Quart 4 3.5 na 25 3.5 na 25 18 nd 18 C—X—C motif chemokine 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 34.7 43.2 34.7 43.2 34.7 46.7 Average 49.8 64.5 49.8 64.5 49.8 45.7 Stdev 49.7 87.6 49.7 87.6 49.7 21.8 p (t-test) 0.44 0.44 0.84 Min 5.55 9.69 5.55 9.69 5.55 17.9 Max 244 336 244 336 244 72.4 n (Samp) 51 12 51 12 51 6 n (Patient) 51 12 51 12 51 6 sCr only Median 27.2 33.4 27.2 33.4 nd nd Average 45.3 34.9 45.3 34.9 nd nd Stdev 50.5 22.4 50.5 22.4 nd nd p (t-test) 0.62 0.62 nd nd Min 4.02 9.69 4.02 9.69 nd nd Max 311 72.4 311 72.4 nd nd n (Samp) 101 6 101 6 nd nd n (Patient) 101 6 101 6 nd nd UO only Median 31.0 46.7 31.0 46.7 31.0 46.7 Average 45.7 81.8 45.7 81.8 45.7 45.7 Stdev 49.1 105 49.1 105 49.1 21.8 p (t-test) 0.12 0.12 1.00 Min 5.55 17.9 5.55 17.9 5.55 17.9 Max 244 336 244 336 244 72.4 n (Samp) 47 8 47 8 47 6 n (Patient) 47 8 47 8 47 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.59 0.51 0.70 0.59 0.51 0.70 0.60 nd 0.65 SE 0.095 0.12 0.11 0.095 0.12 0.11 0.13 nd 0.13 p 0.36 0.92 0.063 0.36 0.92 0.063 0.42 nd 0.24 nCohort 1 51 101 47 51 101 47 51 nd 47 nCohort 2 12 6 8 12 6 8 6 nd 6 Cutoff 1 25.5 17.6 42.8 25.5 17.6 42.8 24.0 nd 24.0 Sens 1 75% 83% 75% 75% 83% 75% 83% nd 83% Spec 1 39% 32% 70% 39% 32% 70% 33% nd 38% Cutoff 2 24.1 17.6 24.1 24.1 17.6 24.1 24.0 nd 24.0 Sens 2 83% 83% 88% 83% 83% 88% 83% nd 83% Spec 2 37% 32% 40% 37% 32% 40% 33% nd 38% Cutoff 3 17.6 8.88 17.6 17.6 8.88 17.6 17.6 nd 17.6 Sens 3 92% 100%  100%  92% 100%  100%  100%  nd 100%  Spec 3 27% 10% 30% 27% 10% 30% 27% nd 30% Cutoff 4 46.9 43.7 42.8 46.9 43.7 42.8 46.9 nd 42.8 Sens 4 33% 17% 75% 33% 17% 75% 50% nd 67% Spec 4 71% 70% 70% 71% 70% 70% 71% nd 70% Cutoff 5 56.7 56.7 51.1 56.7 56.7 51.1 56.7 nd 51.1 Sens 5 25% 17% 38% 25% 17% 38% 33% nd 33% Spec 5 80% 80% 81% 80% 80% 81% 80% nd 81% Cutoff 6 117 95.2 117 117 95.2 117 117 nd 117 Sens 6  8%  0% 12%  8%  0% 12%  0% nd  0% Spec 6 90% 90% 91% 90% 90% 91% 90% nd 91% OR Quart 2 3.2 2.0 >2.2 3.2 2.0 >2.2 >2.3 nd >2.4 p Value 0.34 0.58 <0.55 0.34 0.58 <0.55 <0.51 nd <0.51 95% CI of 0.30 0.17 >0.17 0.30 0.17 >0.17 >0.19 nd >0.19 OR Quart 2 35 23 na 35 23 na na nd na OR Quart 3 6.4 2.0 >2.2 6.4 2.0 >2.2 >2.3 nd >1.1 p Value 0.11 0.58 <0.55 0.11 0.58 <0.55 <0.51 nd <0.96 95% CI of 0.65 0.17 >0.17 0.65 0.17 >0.17 >0.19 nd >0.061 OR Quart 3 63 23 na 63 23 na na nd na OR Quart 4 3.2 0.96 >5.2 3.2 0.96 >5.2 >2.2 nd >3.5 p Value 0.34 0.98 <0.17 0.34 0.98 <0.17 <0.55 nd <0.30 95% CI of 0.30 0.057 >0.50 0.30 0.057 >0.50 >0.17 nd >0.32 OR Quart 4 35 16 na 35 16 na na nd na Coagulation factor VII 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 349 309 349 246 349 230 Average 382 318 382 274 382 298 Stdev 165 193 165 179 165 165 p (t-test) 0.16 0.016 0.17 Min 2.33 32.8 2.33 32.8 2.33 139 Max 743 779 743 779 743 622 n (Samp) 110 16 110 16 110 8 n (Patient) 110 16 110 16 110 8 sCr only Median 344 244 344 222 nd nd Average 368 261 368 231 nd nd Stdev 170 118 170 103 nd nd p (t-test) 0.079 0.025 nd nd Min 2.33 77.8 2.33 75.6 nd nd Max 822 430 822 386 nd nd n (Samp) 180 8 180 8 nd nd n (Patient) 180 8 180 8 nd nd UO only Median 356 358 356 310 356 304 Average 388 368 388 321 388 324 Stdev 169 215 169 206 169 186 p (t-test) 0.73 0.25 0.38 Min 119 32.8 119 32.8 119 139 Max 1020 779 1020 779 1020 622 n (Samp) 91 10 91 10 91 6 n (Patient) 91 10 91 10 91 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.39 0.32 0.48 0.31 0.25 0.39 0.34 nd 0.40 SE 0.079 0.11 0.098 0.077 0.10 0.099 0.11 nd 0.13 p 0.17 0.086 0.82 0.011 0.015 0.28 0.14 nd 0.43 nCohort 1 110 180 91 110 180 91 110 nd 91 nCohort 2 16 8 10 16 8 10 8 nd 6 Cutoff 1 185 190 283 151 190 246 195 nd 150 Sens 1 75% 75% 70% 75% 75% 70% 75% nd 83% Spec 1 11% 15% 26%  9% 15% 19% 13% nd  7% Cutoff 2 173 177 274 138 126 150 151 nd 150 Sens 2 81% 88% 80% 81% 88% 80% 88% nd 83% Spec 2 10% 14% 24%  5%  4%  7%  9% nd  7% Cutoff 3 32.8 53.5 138 32.8 53.5 138 138 nd 138 Sens 3 94% 100%  90% 94% 100%  90% 100%  nd 100%  Spec 3  1%  2%  4%  1%  2%  4%  5% nd  4% Cutoff 4 456 456 437 456 456 437 456 nd 437 Sens 4 12%  0% 30%  6%  0% 20% 12% nd 17% Spec 4 70% 71% 70% 70% 71% 70% 70% nd 70% Cutoff 5 533 510 549 533 510 549 533 nd 549 Sens 5 12%  0% 20%  6%  0% 10% 12% nd 17% Spec 5 80% 80% 80% 80% 80% 80% 80% nd 80% Cutoff 6 646 623 632 646 623 632 646 nd 632 Sens 6  6%  0% 10%  6%  0% 10%  0% nd  0% Spec 6 90% 90% 90% 90% 90% 90% 90% nd 90% OR Quart 2 2.2 >2.1 1.6 3.3 >1.0 3.4 2.1 nd 2.2 p Value 0.38 <0.55 0.61 0.31 <0.99 0.30 0.54 nd 0.54 95% CI of 0.38 >0.18 0.25 0.33 >0.062 0.33 0.18 nd 0.18 OR Quart 2 13 na 11 34 na 35 25 nd 26 OR Quart 3 2.1 >2.1 1.6 4.4 >3.2 2.2 0 nd 0 p Value 0.40 <0.55 0.61 0.19 <0.32 0.54 na nd na 95% CI of 0.36 >0.18 0.25 0.47 >0.32 0.18 na nd na OR Quart 3 13 na 11 42 na 26 na nd na OR Quart 4 3.6 >4.4 1.0 11 >4.4 4.8 6.0 nd 3.4 p Value 0.14 <0.19 0.97 0.030 <0.19 0.18 0.11 nd 0.30 95% CI of 0.67 >0.47 0.14 1.3 >0.47 0.49 0.66 nd 0.33 OR Quart 4 19 na 8.0 92 na 46 55 nd 36 Insulin-like growth factor-binding protein 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 65.8 160 65.8 132 nd nd Average 70.2 181 70.2 174 nd nd Stdev 35.5 120 35.5 121 nd nd p (t-test) 4.1E−8 2.2E−7 nd nd Min 18.6 58.3 18.6 58.3 nd nd Max 250 437 250 437 nd nd n (Samp) 74 8 74 8 nd nd n (Patient) 74 8 74 8 nd nd UO only Median 73.5 114 73.5 114 nd nd Average 76.8 171 76.8 171 nd nd Stdev 35.4 140 35.4 140 nd nd p (t-test) 5.0E−5 5.0E−5 nd nd Min 28.5 58.3 28.5 58.3 nd nd Max 250 437 250 437 nd nd n (Samp) 64 6 64 6 nd nd n (Patient) 64 6 64 6 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.89 nd 0.82 0.88 nd 0.82 nd nd nd SE 0.079 nd 0.11 0.080 nd 0.11 nd nd nd p 9.7E−7 nd 0.0029 1.6E−6 nd 0.0029 nd nd nd nCohort 1 74 nd 64 74 nd 64 nd nd nd nCohort 2 8 nd 6 8 nd 6 nd nd nd Cutoff 1 96.9 nd 91.7 96.9 nd 91.7 nd nd nd Sens 1 75% nd 83% 75% nd 83% nd nd nd Spec 1 86% nd 81% 86% nd 81% nd nd nd Cutoff 2 91.7 nd 91.7 91.7 nd 91.7 nd nd nd Sens 2 88% nd 83% 88% nd 83% nd nd nd Spec 2 85% nd 81% 85% nd 81% nd nd nd Cutoff 3 57.2 nd 58.1 57.2 nd 58.1 nd nd nd Sens 3 100%  nd 100%  100%  nd 100%  nd nd nd Spec 3 45% nd 36% 45% nd 36% nd nd nd Cutoff 4 79.2 nd 84.3 79.2 nd 84.3 nd nd nd Sens 4 88% nd 83% 88% nd 83% nd nd nd Spec 4 70% nd 70% 70% nd 70% nd nd nd Cutoff 5 87.0 nd 91.7 87.0 nd 91.7 nd nd nd Sens 5 88% nd 83% 88% nd 83% nd nd nd Spec 5 81% nd 81% 81% nd 81% nd nd nd Cutoff 6 114 nd 115 114 nd 115 nd nd nd Sens 6 62% nd 50% 62% nd 50% nd nd nd Spec 6 91% nd 91% 91% nd 91% nd nd nd OR Quart 2 >1.0 nd >1.0 >1.0 nd >1.0 nd nd nd p Value <1.0 nd <1.0 <1.0 nd <1.0 nd nd nd 95% CI of >0.058 nd >0.058 >0.058 nd >0.058 nd nd nd OR Quart 2 na nd na na nd na nd nd nd OR Quart 3 >0 nd >0 >0 nd >0 nd nd nd p Value <na nd <na <na nd <na nd nd nd 95% CI of >na nd >na >na nd >na nd nd nd OR Quart 3 na nd na na nd na nd nd nd OR Quart 4 >10 nd >6.5 >10 nd >6.5 nd nd nd p Value <0.041 nd <0.10 <0.041 nd <0.10 nd nd nd 95% CI of >1.1 nd >0.68 >1.1 nd >0.68 nd nd nd OR Quart 4 na nd na na nd na nd nd nd

TABLE 9 Comparison of marker levels in urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0, R, or I) and in urine samples collected from Cohort 2 (subjects who progress to RIFLE stage F) at 0, 24 hours, and 48 hours prior to the subject reaching RIFLE stage I. Cancer Antigen 19-9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 22.9 38.8 22.9 42.2 nd nd Average 145 35.3 145 391 nd nd Stdev 710 21.1 710 917 nd nd p(t-test) 0.68 0.28 nd nd Min 1.00E−9 6.51 1.00E−9 18.6 nd nd Max 11900 59.3 11900 2940 nd nd n (Samp) 324 7 324 10 nd nd n (Patient) 190 7 190 10 nd nd UO only Median nd nd 25.8 38.7 nd nd Average nd nd 156 476 nd nd Stdev nd nd 755 1020 nd nd p(t-test) nd nd 0.24 nd nd Min nd nd 1.00E−9 18.6 nd nd Max nd nd 11900 2940 nd nd n (Samp) nd nd 283 8 nd nd n (Patient) nd nd 159 8 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.54 nd nd 0.67 nd 0.65 nd nd nd SE 0.11 nd nd 0.095 nd 0.11 nd nd nd p 0.71 nd nd 0.068 nd 0.16 nd nd nd nCohort 1 324 nd nd 324 nd 283 nd nd nd nCohort 2 7 nd nd 10 nd 8 nd nd nd Cutoff 1 36.7 nd nd 27.5 nd 21.8 nd nd nd Sens 1 71% nd nd 70% nd 75% nd nd nd Spec 1 64% nd nd 56% nd 45% nd nd nd Cutoff 2 6.59 nd nd 21.9 nd 20.7 nd nd nd Sens 2 86% nd nd 80% nd 88% nd nd nd Spec 2 22% nd nd 48% nd 43% nd nd nd Cutoff 3 6.42 nd nd 20.7 nd 18.5 nd nd nd Sens 3 100%  nd nd 90% nd 100%  nd nd nd Spec 3 21% nd nd 47% nd 41% nd nd nd Cutoff 4 54.2 nd nd 54.2 nd 57.7 nd nd nd Sens 4 14% nd nd 40% nd 38% nd nd nd Spec 4 70% nd nd 70% nd 70% nd nd nd Cutoff 5 102 nd nd 102 nd 116 nd nd nd Sens 5  0% nd nd 20% nd 25% nd nd nd Spec 5 80% nd nd 80% nd 80% nd nd nd Cutoff 6 240 nd nd 240 nd 277 nd nd nd Sens 6  0% nd nd 20% nd 25% nd nd nd Spec 6 90% nd nd 90% nd 90% nd nd nd OR Quart 2 0 nd nd >3.1 nd >3.1 nd nd nd p Value na nd nd <0.34 nd <0.33 nd nd nd 95% CI of na nd nd >0.31 nd >0.31 nd nd nd OR Quart2 na nd nd na nd na nd nd nd OR Quart 3 2.6 nd nd >3.1 nd >2.0 nd nd nd p Value 0.27 nd nd <0.33 nd <0.57 nd nd nd 95% CI of 0.48 nd nd >0.32 nd >0.18 nd nd nd OR Quart3 14 nd nd na nd na nd nd nd OR Quart 4 0 nd nd >4.2 nd >3.1 nd nd nd p Value na nd nd <0.21 nd <0.33 nd nd nd 95% CI of na nd nd >0.45 nd >0.31 nd nd nd OR Quart4 na nd nd na nd na nd nd nd C-C motif chemokine 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 1.00E−9 1.00E−9 1.00E−9 3.52 1.00E−9 1.00E−9 Average 2.67 13.6 2.67 22.2 2.67 8.85 Stdev 16.4 40.1 16.4 35.5 16.4 23.4 p(t-test) 0.021 5.2E−6  0.32 Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 1.00E−9 Max 241 143 241 101 241 61.9 n (Samp) 937 13 937 16 937 7 n (Patient) 345 13 345 16 345 7 sCr only Median 1.00E−9 1.00E−9 nd nd nd nd Average 3.18 1.00E−9 nd nd nd nd Stdev 17.6 0 nd nd nd nd p(t-test) 0.63 nd nd nd nd Min 1.00E−9 1.00E−9 nd nd nd nd Max 241 1.00E−9 nd nd nd nd n (Samp) 974 7 nd nd nd nd n (Patient) 355 7 nd nd nd nd UO only Median 1.00E−9 1.00E−9 1.00E−9 3.52 nd nd Average 2.68 17.9 2.68 24.8 nd nd Stdev 17.0 50.7 17.0 37.3 nd nd p(t-test) 0.015 3.1E−6  nd nd Min 1.00E−9 1.00E−9 1.00E−9 1.00E−9 nd nd Max 241 143 241 101 nd nd n (Samp) 804 8 804 14 nd nd n (Patient) 264 8 264 14 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.55 0.46 0.53 0.72 nd 0.72 0.54 nd nd SE 0.083 0.11 0.10 0.073 nd 0.078 0.11 nd nd p 0.56 0.75 0.74 0.0028 nd 0.0046 0.71 nd nd nCohort 1 937 974 804 937 nd 804 937 nd nd nCohort 2 13 7 8 16 nd 14 7 nd nd Cutoff 1 0 0 0 0 nd 0 0 nd nd Sens 1 100%  100%  100%  100%  nd 100%  100%  nd nd Spec 1  0% 0%  0%  0% nd  0%  0% nd nd Cutoff 2 0 0 0 0 nd 0 0 nd nd Sens 2 100%  100%  100%  100%  nd 100%  100%  nd nd Spec 2  0% 0%  0%  0% nd  0%  0% nd nd Cutoff 3 0 0 0 0 nd 0 0 nd nd Sens 3 100%  100%  100%  100%  nd 100%  100%  nd nd Spec 3  0% 0%  0%  0% nd  0%  0% nd nd Cutoff 4 1.00E−9 1.00E−9 1.00E−9 1.00E−9 nd 1.00E−9 1.00E−9 nd nd Sens 4 15% 0% 12% 50% nd 50% 14% nd nd Spec 4 93% 93%  94% 93% nd 94% 93% nd nd Cutoff 5 1.00E−9 1.00E−9 1.00E−9 1.00E−9 nd 1.00E−9 1.00E−9 nd nd Sens 5 15% 0% 12% 50% nd 50% 14% nd nd Spec 5 93% 93%  94% 93% nd 94% 93% nd nd Cutoff 6 1.00E−9 1.00E−9 1.00E−9 1.00E−9 nd 1.00E−9 1.00E−9 nd nd Sens 6 15% 0% 12% 50% nd 50% 14% nd nd Spec 6 93% 93%  94% 93% nd 94% 93% nd nd OR Quart 2 >11 >0 >7.2 >8.3 nd >7.2 >6.2 nd nd p Value <0.020 <na <0.065 <0.047 nd <0.066 <0.094 nd nd 95% CI of >1.5 >na >0.88 >1.0 nd >0.88 >0.74 nd nd OR Quart2 na   na na na nd na na nd nd OR Quart 3 >0 >7.2 >0 >0 nd >0 >0 nd nd p Value <na   <0.065 <na   <na   nd <na   <na   nd nd 95% CI of >na   >0.88 >na   >na   nd >na   >na   nd nd OR Quart3 na   na na na nd na na nd nd OR Quart 4 >2.0 >0 >1.0 >8.2 nd >7.2 >1.0 nd nd p Value <0.57 <na <1.00 <0.048 nd <0.066 <1.00 nd nd 95% CI of >0.18 >na >0.062 >1.0 nd >0.88 >0.062 nd nd OR Quart4 na   na na na nd na na nd nd C-X-C motif chemokine 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 15.5 19.3 15.5 82.0 15.5 8.72 Average 35.9 206 35.9 201 35.9 26.6 Stdev 106 453 106 252 106 50.3 p(t-test) 2.4E−7 3.5E−9 0.82 Min 1.00E−9 1.62 1.00E−9 9.04 1.00E−9 0.506 Max 2500 1450 2500 769 2500 140 n (Samp) 935 13 935 16 935 7 n (Patient) 345 13 345 16 345 7 sCr only Median 15.9 61.3 nd nd nd nd Average 40.3 281 nd nd nd nd Stdev 116 530 nd nd nd nd p(t-test) 2.8E−7 nd nd nd nd Min 1.00E−9 1.62 nd nd nd nd Max 2500 1450 nd nd nd nd n (Samp) 972 7 nd nd nd nd n (Patient) 355 7 nd nd nd nd UO only Median 17.0 40.1 17.0 99.7 nd nd Average 37.5 320 37.5 225 nd nd Stdev 112 560 112 262 nd nd p(t-test)  2.0E−10 3.5E−9 nd nd Min 1.00E−9 3.96 1.00E−9 9.04 nd nd Max 2500 1450 2500 769 nd nd n (Samp) 802 8 802 14 nd nd n (Patient) 264 8 264 14 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.58 0.65 0.62 0.83 nd 0.84 0.37 nd nd SE 0.083 0.11 0.11 0.063 nd 0.067 0.11 nd nd p 0.36 0.20 0.28 2.1E−7 nd 4.1E−7 0.25 nd nd nCohort 1 935 972 802 935 nd 802 935 nd nd nCohort 2 13 7 8 16 nd 14 7 nd nd Cutoff 1 7.87 11.6 7.87 48.3 nd 51.2 4.01 nd nd Sens 1 77% 71% 75% 75% nd 71% 71% nd nd Spec 1 31% 39% 28% 84% nd 85% 17% nd nd Cutoff 2 5.34 7.91 5.34 24.7 nd 24.5 0.534 nd nd Sens 2 85% 86% 88% 81% nd 86% 86% nd nd Spec 2 22% 31% 19% 64% nd 62%  5% nd nd Cutoff 3 3.84 1.62 3.83 12.0 nd 12.0 0.437 nd nd Sens 3 92% 100%  100%  94% nd 93% 100%  nd nd Spec 3 16%  8% 13% 41% nd 38%  4% nd nd Cutoff 4 29.2 30.3 30.1 29.2 nd 30.1 29.2 nd nd Sens 4 46% 57% 50% 75% nd 79% 14% nd nd Spec 4 70% 70% 70% 70% nd 70% 70% nd nd Cutoff 5 40.3 43.6 41.1 40.3 nd 41.1 40.3 nd nd Sens 5 38% 57% 50% 75% nd 79% 14% nd nd Spec 5 80% 80% 80% 80% nd 80% 80% nd nd Cutoff 6 63.9 69.4 63.9 63.9 nd 63.9 63.9 nd nd Sens 6 23% 29% 25% 56% nd 64% 14% nd nd Spec 6 90% 90% 90% 90% nd 90% 90% nd nd OR Quart 2 1.0 2.0 0.50 >2.0 nd >2.0 1.0 nd nd p Value 1.0 0.57 0.57 <0.57 nd <0.57 1.00 nd nd 95% CI of 0.20 0.18 0.045 >0.18 nd >0.18 0.062 nd nd OR Quart2 5.0 22 5.5 na nd na 16 nd nd OR Quart 3 0.66 0 0.50 >2.0 nd >1.0 2.0 nd nd p Value 0.66 na 0.57 <0.57 nd <1.00 0.57 nd nd 95% CI of 0.11 na 0.045 >0.18 nd >0.062 0.18 nd nd OR Quart3 4.0 na 5.5 na nd na 22 nd nd OR Quart 4 1.7 4.0 2.0 >13 nd >12 3.0 nd nd p Value 0.48 0.21 0.42 <0.015 nd <0.019 0.34 nd nd 95% CI of 0.40 0.45 0.36 >1.6 nd >1.5 0.31 nd nd OR Quart4 7.1 36 11 na nd na 29 nd nd Coagulation factor VII 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 3.14 3.73 3.14 2.84 nd nd Average 6.63 5.14 6.63 7.07 nd nd Stdev 13.6 5.61 13.6 8.20 nd nd p(t-test) 0.73 0.92 nd nd Min 0.00408 0.348 0.00408 0.682 nd nd Max 249 18.9 249 24.9 nd nd n (Samp) 534 10 534 11 nd nd n (Patient) 204 10 204 11 nd nd UO only Median 3.08 4.33 3.08 2.79 nd nd Average 6.47 4.83 6.47 5.67 nd nd Stdev 14.1 2.60 14.1 6.68 nd nd p(t-test) 0.76 0.87 nd nd Min 0.00408 0.550 0.00408 0.682 nd nd Max 249 8.18 249 19.4 nd nd n (Samp) 454 7 454 8 nd nd n (Patient) 168 7 168 8 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.48 nd 0.57 0.55 nd 0.52 nd nd nd SE 0.093 nd 0.11 0.090 nd 0.10 nd nd nd p 0.87 nd 0.52 0.55 nd 0.88 nd nd nd nCohort 1 534 nd 454 534 nd 454 nd nd nd nCohort 2 10 nd 7 11 nd 8 nd nd nd Cutoff 1 2.27 nd 4.15 2.34 nd 2.34 nd nd nd Sens 1 70% nd 71% 73% nd 75% nd nd nd Spec 1 40% nd 59% 41% nd 42% nd nd nd Cutoff 2 0.539 nd 3.28 2.16 nd 1.50 nd nd nd Sens 2 80% nd 86% 82% nd 88% nd nd nd Spec 2 11% nd 51% 39% nd 31% nd nd nd Cutoff 3 0.420 nd 0.539 1.50 nd 0.676 nd nd nd Sens 3 90% nd 100%  91% nd 100%  nd nd nd Spec 3  7% nd 11% 31% nd 13% nd nd nd Cutoff 4 6.36 nd 6.11 6.36 nd 6.11 nd nd nd Sens 4 30% nd 29% 27% nd 25% nd nd nd Spec 4 70% nd 70% 70% nd 70% nd nd nd Cutoff 5 9.31 nd 8.93 9.31 nd 8.93 nd nd nd Sens 5 10% nd  0% 27% nd 25% nd nd nd Spec 5 80% nd 80% 80% nd 80% nd nd nd Cutoff 6 15.0 nd 14.3 15.0 nd 14.3 nd nd nd Sens 6 10% nd  0% 18% nd 12% nd nd nd Spec 6 90% nd 91% 90% nd 91% nd nd nd OR Quart 2 2.0 nd 0 5.2 nd 4.1 nd nd nd p Value 0.42 nd na 0.14 nd 0.21 nd nd nd 95% CI of 0.37 nd na 0.59 nd 0.45 nd nd nd OR Quart2 11 nd na 45 nd 37 nd nd nd OR Quart 3 0.50 nd 4.1 2.0 nd 1.0 nd nd nd p Value 0.57 nd 0.21 0.57 nd 1.0 nd nd nd 95% CI of 0.044 nd 0.45 0.18 nd 0.062 nd nd nd OR Quart3 5.5 nd 37 22 nd 16 nd nd nd OR Quart 4 1.5 nd 2.0 3.0 nd 2.0 nd nd nd p Value 0.65 nd 0.57 0.34 nd 0.57 nd nd nd 95% CI of 0.25 nd 0.18 0.31 nd 0.18 nd nd nd OR Quart4 9.2 nd 22 29 nd 22 nd nd nd Insulin-like growth factor-binding protein 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 52.8 68.7 52.8 226 52.8 102 Average 76.8 280 76.8 332 76.8 151 Stdev 80.0 492 80.0 315 80.0 123 p(t-test) 1.4E−13 3.2E−28 0.015 Min 1.00E−9 23.1 1.00E−9 20.4 1.00E−9 33.8 Max 694 1830 694 1250 694 382 n (Samp) 933 13 933 16 933 7 n (Patient) 344 13 344 16 344 7 sCr only Median 54.0 163 nd nd nd nd Average 84.3 201 nd nd nd nd Stdev 111 203 nd nd nd nd p(t-test) 0.0058 nd nd nd nd Min 1.00E−9 23.1 nd nd nd nd Max 1830 594 nd nd nd nd n (Samp) 970 7 nd nd nd nd n (Patient) 354 7 nd nd nd nd UO only Median 53.6 114 53.6 283 nd nd Average 76.5 375 76.5 354 nd nd Stdev 76.0 615 76.0 332 nd nd p(t-test) 5.7E−18 2.0E−30 nd nd Min 1.00E−9 46.5 1.00E−9 20.4 nd nd Max 543 1830 543 1250 nd nd n (Samp) 800 8 800 14 nd nd n (Patient) 263 8 263 14 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.69 0.70 0.73 0.86 nd 0.85 0.73 nd nd SE 0.082 0.11 0.10 0.059 nd 0.065 0.11 nd nd p 0.023 0.069 0.024 1.8E−9 nd 5.3E−8 0.037 nd nd nCohort 1 933 970 800 933 nd 800 933 nd nd nCohort 2 13 7 8 16 nd 14 7 nd nd Cutoff 1 49.1 68.6 57.5 118 nd 118 74.9 nd nd Sens 1 77% 71% 75% 75% nd 71% 71% nd nd Spec 1 47% 61% 54% 82% nd 82% 67% nd nd Cutoff 2 46.5 39.0 49.1 104 nd 99.9 51.8 nd nd Sens 2 85% 86% 88% 81% nd 86% 86% nd nd Spec 2 45% 35% 46% 79% nd 78% 49% nd nd Cutoff 3 39.0 23.1 46.5 65.8 nd 65.8 33.8 nd nd Sens 3 92% 100%  100%  94% nd 93% 100%  nd nd Spec 3 36% 19% 44% 61% nd 60% 30% nd nd Cutoff 4 82.1 84.7 82.1 82.1 nd 82.1 82.1 nd nd Sens 4 46% 57% 50% 88% nd 86% 57% nd nd Spec 4 70% 70% 70% 70% nd 70% 70% nd nd Cutoff 5 110 118 110 110 nd 110 110 nd nd Sens 5 46% 57% 50% 75% nd 71% 43% nd nd Spec 5 80% 80% 80% 80% nd 80% 80% nd nd Cutoff 6 159 175 159 159 nd 159 159 nd nd Sens 6 46% 43% 50% 56% nd 57% 43% nd nd Spec 6 90% 90% 90% 90% nd 90% 90% nd nd OR Quart 2 3.0 1.0 >2.0 0 nd 0 >2.0 nd nd p Value 0.34 1.0 <0.57 na nd na <0.57 nd nd 95% CI of 0.31 0.062 >0.18 na nd na >0.18 nd nd OR Quart2 29 16 na na nd na na nd nd OR Quart 3 3.0 1.0 >2.0 1.0 nd 1.0 >1.0 nd nd p Value 0.34 1.0 <0.57 1.0 nd 1.0 <1.00 nd nd 95% CI of 0.31 0.062 >0.18 0.062 nd 0.062 >0.062 nd nd OR Quart3 29 16 na 16 nd 16 na nd nd OR Quart 4 6.1 4.0 >4.1 15 nd 13 >4.1 nd nd p Value 0.095 0.21 <0.21 0.0096 nd 0.015 <0.21 nd nd 95% CI of 0.73 0.45 >0.45 1.9 nd 1.6 >0.45 nd nd OR Quart4 51 36 na 110 nd 98 na nd nd

TABLE 10 Comparison of marker levels in EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0, R, or I) and in EDTA samples collected from Cohort 2 (subjects who progress to RIFLE stage F) at 0, 24 hours, and 48 hours prior to the subject reaching RIFLE stage I. Cancer Antigen 19-9 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median nd nd 0.244 0.663 nd nd Average nd nd 0.645 1.43 nd nd Stdev nd nd 2.70 1.89 nd nd p(t-test) nd nd 0.48 nd nd Min nd nd 1.00E−9 0.401 nd nd Max nd nd 41.6 5.26 nd nd n (Samp) nd nd 248 6 nd nd n (Patient) nd nd 158 6 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC nd nd nd 0.82 nd nd nd nd nd SE nd nd nd 0.11 nd nd nd nd nd p nd nd nd 0.0022 nd nd nd nd nd nCohort 1 nd nd nd 248 nd nd nd nd nd nCohort 2 nd nd nd 6 nd nd nd nd nd Cutoff 1 nd nd nd 0.586 nd nd nd nd nd Sens 1 nd nd nd 83% nd nd nd nd nd Spec 1 nd nd nd 77% nd nd nd nd nd Cutoff 2 nd nd nd 0.586 nd nd nd nd nd Sens 2 nd nd nd 83% nd nd nd nd nd Spec 2 nd nd nd 77% nd nd nd nd nd Cutoff 3 nd nd nd 0.374 nd nd nd nd nd Sens 3 nd nd nd 100%  nd nd nd nd nd Spec 3 nd nd nd 67% nd nd nd nd nd Cutoff 4 nd nd nd 0.452 nd nd nd nd nd Sens 4 nd nd nd 83% nd nd nd nd nd Spec 4 nd nd nd 71% nd nd nd nd nd Cutoff 5 nd nd nd 0.633 nd nd nd nd nd Sens 5 nd nd nd 50% nd nd nd nd nd Spec 5 nd nd nd 81% nd nd nd nd nd Cutoff 6 nd nd nd 1.41 nd nd nd nd nd Sens 6 nd nd nd 17% nd nd nd nd nd Spec 6 nd nd nd 90% nd nd nd nd nd OR Quart 2 nd nd nd >0 nd nd nd nd nd p Value nd nd nd <na   nd nd nd nd nd 95% CI of nd nd nd >na   nd nd nd nd nd OR Quart2 nd nd nd na nd nd nd nd nd OR Quart 3 nd nd nd >1.0 nd nd nd nd nd p Value nd nd nd <0.99 nd nd nd nd nd 95% CI of nd nd nd >0.062 nd nd nd nd nd OR Quart3 nd nd nd na nd nd nd nd nd OR Quart 4 nd nd nd >5.3 nd nd nd nd nd p Value nd nd nd <0.13 nd nd nd nd nd 95% CI of nd nd nd >0.61 nd nd nd nd nd OR Quart4 nd nd nd na nd nd nd nd nd C-C motif chemokine 13 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median nd nd 21.0 30.9 nd nd Average nd nd 61.7 29.1 nd nd Stdev nd nd 207 27.1 nd nd p(t-test) nd nd 0.70 nd nd Min nd nd 1.00E−9 1.00E−9 nd nd Max nd nd 2520 68.2 nd nd n (Samp) nd nd 177 6 nd nd n (Patient) nd nd 126 6 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC nd nd nd 0.50 nd nd nd nd nd SE nd nd nd 0.12 nd nd nd nd nd p nd nd nd 0.99 nd nd nd nd nd nCohort 1 nd nd nd 177 nd nd nd nd nd nCohort 2 nd nd nd 6 nd nd nd nd nd Cutoff 1 nd nd nd 0 nd nd nd nd nd Sens 1 nd nd nd 100%  nd nd nd nd nd Spec 1 nd nd nd 0% nd nd nd nd nd Cutoff 2 nd nd nd 0 nd nd nd nd nd Sens 2 nd nd nd 100%  nd nd nd nd nd Spec 2 nd nd nd 0% nd nd nd nd nd Cutoff 3 nd nd nd 0 nd nd nd nd nd Sens 3 nd nd nd 100%  nd nd nd nd nd Spec 3 nd nd nd 0% nd nd nd nd nd Cutoff 4 nd nd nd 54.3 nd nd nd nd nd Sens 4 nd nd nd 17%  nd nd nd nd nd Spec 4 nd nd nd 71%  nd nd nd nd nd Cutoff 5 nd nd nd 72.2 nd nd nd nd nd Sens 5 nd nd nd 0% nd nd nd nd nd Spec 5 nd nd nd 81%  nd nd nd nd nd Cutoff 6 nd nd nd 111 nd nd nd nd nd Sens 6 nd nd nd 0% nd nd nd nd nd Spec 6 nd nd nd 90%  nd nd nd nd nd OR Quart 2 nd nd nd 2.0 nd nd nd nd nd p Value nd nd nd 0.56 nd nd nd nd nd 95% CI of nd nd nd 0.18 nd nd nd nd nd OR Quart2 nd nd nd 23 nd nd nd nd nd OR Quart 3 nd nd nd 3.1 nd nd nd nd nd p Value nd nd nd 0.33 nd nd nd nd nd 95% CI of nd nd nd 0.31 nd nd nd nd nd OR Quart3 nd nd nd 31 nd nd nd nd nd OR Quart 4 nd nd nd 0 nd nd nd nd nd p Value nd nd nd na nd nd nd nd nd 95% CI of nd nd nd na nd nd nd nd nd OR Quart4 nd nd nd na nd nd nd nd nd C-X-C motif chemokine 6 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median nd nd 28.2 32.4 nd nd Average nd nd 45.6 31.0 nd nd Stdev nd nd 50.4 15.9 nd nd p(t-test) nd nd 0.48 nd nd Min nd nd 3.49 9.69 nd nd Max nd nd 311 48.8 nd nd n (Samp) nd nd 178 6 nd nd n (Patient) nd nd 127 6 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC nd nd nd 0.49 nd nd nd nd nd SE nd nd nd 0.12 nd nd nd nd nd p nd nd nd 0.96 nd nd nd nd nd nCohort 1 nd nd nd 178 nd nd nd nd nd nCohort 2 nd nd nd 6 nd nd nd nd nd Cutoff 1 nd nd nd 17.9 nd nd nd nd nd Sens 1 nd nd nd 83% nd nd nd nd nd Spec 1 nd nd nd 34% nd nd nd nd nd Cutoff 2 nd nd nd 17.9 nd nd nd nd nd Sens 2 nd nd nd 83% nd nd nd nd nd Spec 2 nd nd nd 34% nd nd nd nd nd Cutoff 3 nd nd nd 9.55 nd nd nd nd nd Sens 3 nd nd nd 100%  nd nd nd nd nd Spec 3 nd nd nd  9% nd nd nd nd nd Cutoff 4 nd nd nd 45.4 nd nd nd nd nd Sens 4 nd nd nd 17% nd nd nd nd nd Spec 4 nd nd nd 70% nd nd nd nd nd Cutoff 5 nd nd nd 63.5 nd nd nd nd nd Sens 5 nd nd nd  0% nd nd nd nd nd Spec 5 nd nd nd 80% nd nd nd nd nd Cutoff 6 nd nd nd 107 nd nd nd nd nd Sens 6 nd nd nd  0% nd nd nd nd nd Spec 6 nd nd nd 90% nd nd nd nd nd OR Quart 2 nd nd nd >3.2 nd nd nd nd nd p Value nd nd nd <0.32 nd nd nd nd nd 95% CI of nd nd nd >0.32 nd nd nd nd nd OR Quart2 nd nd nd na nd nd nd nd nd OR Quart 3 nd nd nd >2.1 nd nd nd nd nd p Value nd nd nd <0.55 nd nd nd nd nd 95% CI of nd nd nd >0.18 nd nd nd nd nd OR Quart3 nd nd nd na nd nd nd nd nd OR Quart 4 nd nd nd >1.0 nd nd nd nd nd p Value nd nd nd <0.99 nd nd nd nd nd 95% CI of nd nd nd >0.062 nd nd nd nd nd OR Quart4 nd nd nd na nd nd nd nd nd Coagulation factor VII 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 sCr or UO Median 301 274 301 191 nd nd Average 321 283 321 218 nd nd Stdev 174 138 174 135 nd nd p(t-test) 0.45 0.052 nd nd Min 2.08 77.8 2.08 32.8 nd nd Max 1020 549 1020 418 nd nd n (Samp) 551 12 551 11 nd nd n (Patient) 213 12 213 11 nd nd UO only Median 289 379 289 286 nd nd Average 307 384 307 231 nd nd Stdev 165 151 165 138 nd nd p(t-test) 0.19 0.18 nd nd Min 8.62 158 8.62 32.8 nd nd Max 1020 611 1020 418 nd nd n (Samp) 465 8 465 9 nd nd n (Patient) 174 8 174 9 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC 0.45 nd 0.65 0.33 nd 0.38 nd nd nd SE 0.087 nd 0.11 0.091 nd 0.10 nd nd nd p 0.54 nd 0.16 0.067 nd 0.23 nd nd nd nCohort 1 551 nd 465 551 nd 465 nd nd nd nCohort 2 12 nd 8 11 nd 9 nd nd nd Cutoff 1 192 nd 283 101 nd 100 nd nd nd Sens 1 75% nd 75% 73% nd 78% nd nd nd Spec 1 28% nd 49%  8% nd  8% nd nd nd Cutoff 2 156 nd 261 79.5 nd 79.5 nd nd nd Sens 2 83% nd 88% 82% nd 89% nd nd nd Spec 2 18% nd 45%  5% nd  6% nd nd nd Cutoff 3 130 nd 156 74.8 nd 25.4 nd nd nd Sens 3 92% nd 100%  91% nd 100%  nd nd nd Spec 3 12% nd 19%  5% nd  1% nd nd nd Cutoff 4 403 nd 383 403 nd 383 nd nd nd Sens 4 17% nd 38%  9% nd 11% nd nd nd Spec 4 70% nd 70% 70% nd 70% nd nd nd Cutoff 5 469 nd 448 469 nd 448 nd nd nd Sens 5  8% nd 38%  0% nd  0% nd nd nd Spec 5 80% nd 80% 80% nd 80% nd nd nd Cutoff 6 563 nd 530 563 nd 530 nd nd nd Sens 6  0% nd 25%  0% nd  0% nd nd nd Spec 6 90% nd 90% 90% nd 90% nd nd nd OR Quart 2 1.0 nd 2.0 >5.2 nd 3.1 nd nd nd p Value 1.0 nd 0.57 <0.13 nd 0.33 nd nd nd 95% CI of 0.14 nd 0.18 >0.60 nd 0.32 nd nd nd OR Quart2 7.2 nd 23 na nd 30 nd nd nd OR Quart 3 2.6 nd 2.0 >1.0 nd 1.0 nd nd nd p Value 0.27 nd 0.57 <1.00 nd 1.0 nd nd nd 95% CI of 0.49 nd 0.18 >0.062 nd 0.062 nd nd nd OR Quart3 13 nd 23 na nd 16 nd nd nd OR Quart 4 1.5 nd 3.0 >5.2 nd 4.1 nd nd nd p Value 0.65 nd 0.34 <0.13 nd 0.21 nd nd nd 95% CI of 0.25 nd 0.31 >0.60 nd 0.46 nd nd nd OR Quart4 9.3 nd 30 na nd 38 nd nd nd nsulin-like growth factor-binding protein 7 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median nd nd 69.2 172 nd nd Average nd nd 74.9 194 nd nd Stdev nd nd 32.9 137 nd nd p(t-test) nd nd 6.6E−13 nd nd Min nd nd 18.6 53.8 nd nd Max nd nd 250 437 nd nd n (Samp) nd nd 248 6 nd nd n (Patient) nd nd 158 6 nd nd 0 hr prior to AKI stage 24 hr prior to AKI stage 48 hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only AUC nd nd nd 0.84 nd nd nd nd nd SE nd nd nd 0.10 nd nd nd nd nd p nd nd nd 9.7E−4 nd nd nd nd nd nCohort 1 nd nd nd 248 nd nd nd nd nd nCohort 2 nd nd nd 6 nd nd nd nd nd Cutoff 1 nd nd nd 93.0 nd nd nd nd nd Sens 1 nd nd nd 83% nd nd nd nd nd Spec 1 nd nd nd 78% nd nd nd nd nd Cutoff 2 nd nd nd 93.0 nd nd nd nd nd Sens 2 nd nd nd 83% nd nd nd nd nd Spec 2 nd nd nd 78% nd nd nd nd nd Cutoff 3 nd nd nd 53.5 nd nd nd nd nd Sens 3 nd nd nd 100%  nd nd nd nd nd Spec 3 nd nd nd 30% nd nd nd nd nd Cutoff 4 nd nd nd 85.5 nd nd nd nd nd Sens 4 nd nd nd 83% nd nd nd nd nd Spec 4 nd nd nd 70% nd nd nd nd nd Cutoff 5 nd nd nd 96.3 nd nd nd nd nd Sens 5 nd nd nd 67% nd nd nd nd nd Spec 5 nd nd nd 80% nd nd nd nd nd Cutoff 6 nd nd nd 116 nd nd nd nd nd Sens 6 nd nd nd 67% nd nd nd nd nd Spec 6 nd nd nd 90% nd nd nd nd nd OR Quart 2 nd nd nd >1.0 nd nd nd nd nd p Value nd nd nd <1.0 nd nd nd nd nd 95% CI of nd nd nd >0.061 nd nd nd nd nd OR Quart2 nd nd nd na nd nd nd nd nd OR Quart 3 nd nd nd >0 nd nd nd nd nd p Value nd nd nd <na   nd nd nd nd nd 95% CI of nd nd nd >na   nd nd nd nd nd OR Quart3 nd nd nd na nd nd nd nd nd OR Quart 4 nd nd nd >5.3 nd nd nd nd nd p Value nd nd nd <0.13 nd nd nd nd nd 95% CI of nd nd nd >0.61 nd nd nd nd nd OR Quart4 nd nd nd na nd nd nd nd nd

TABLE 11 Comparison of marker levels in enroll urine samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R within 48 hrs) and in enroll urine samples collected from Cohort 2 (subjects reaching RIFLE stage I or F within 48 hrs). Enroll samples from patients already at RIFLE stage I or F were included in Cohort 2. Cancer Antigen 19-9 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 26.6 42.2 nd nd 27.4 51.5 Average 107 282 nd nd 106 305 Stdev 259 668 nd nd 256 694 p(t-test) 0.036 nd nd 0.030 Min 1.00E−9 1.00E−9 nd nd 1.00E−9 1.00E−9 Max 2000 2940 nd nd 2000 2940 n (Samp) 109 24 nd nd 90 22 n (Patient) 109 24 nd nd 90 22 At Enrollment sCr or UO sCr only UO only AUC 0.60 nd 0.60 SE 0.066 nd 0.070 p 0.15 nd 0.13 nCohort 1 109 nd 90 nCohort 2 24 nd 22 Cutoff 1 23.0 nd 23.0 Sens 1 71% nd 73% Spec 1 46% nd 42% Cutoff 2 9.92 nd 18.7 Sens 2 83% nd 82% Spec 2 27% nd 39% Cutoff 3 5.76 nd 9.72 Sens 3 92% nd 91% Spec 3 20% nd 26% Cutoff 4 63.8 nd 57.3 Sens 4 33% nd 45% Spec 4 71% nd 70% Cutoff 5 117 nd 114 Sens 5 33% nd 36% Spec 5 81% nd 80% Cutoff 6 240 nd 240 Sens 6 17% nd 18% Spec 6 91% nd 90% OR Quart 2 1.3 nd 1.3 p Value 0.72 nd 0.72 95% CI of 0.31 nd 0.31 OR Quart2 5.3 nd 5.5 OR Quart 3 2.0 nd 1.3 p Value 0.33 nd 0.72 95% CI of 0.51 nd 0.31 OR Quart3 7.4 nd 5.5 OR Quart 4 2.2 nd 2.4 p Value 0.23 nd 0.20 95% CI of 0.60 nd 0.63 OR Quart4 8.3 nd 9.2 C-X-C motif chemokine 6 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 13.3 33.1 15.0 42.2 14.9 33.4 Average 27.7 104 38.1 120 28.4 111 Stdev 53.4 188 90.0 195 51.5 197 p(t-test) 6.4E−9 0.0036 8.9E−8 Min 1.00E−9 1.62 1.00E−9 1.62 1.00E−9 3.96 Max 561 909 909 698 561 909 n (Samp) 296 61 342 12 217 55 n (Patient) 296 61 342 12 217 55 At Enrollment sCr or UO sCr only UO only AUC 0.71 0.70 0.71 SE 0.039 0.086 0.042 p 7.0E−8 0.017 8.0E−7 nCohort 1 296 342 217 nCohort 2 61 12 55 Cutoff 1 17.2 18.8 17.2 Sens 1 70% 75% 71% Spec 1 58% 58% 55% Cutoff 2 11.5 11.5 12.3 Sens 2 80% 83% 80% Spec 2 45% 41% 44% Cutoff 3 8.44 10.6 8.22 Sens 3 90% 92% 91% Spec 3 38% 40% 34% Cutoff 4 26.0 28.7 27.4 Sens 4 57% 58% 58% Spec 4 70% 70% 70% Cutoff 5 37.4 42.2 37.4 Sens 5 48% 50% 49% Spec 5 80% 80% 80% Cutoff 6 53.8 62.4 53.8 Sens 6 33% 42% 33% Spec 6 90% 90% 90% OR Quart 2 1.8 2.0 2.4 p Value 0.30 0.57 0.12 95% CI of 0.61 0.18 0.80 OR Quart2 5.0 22 7.4 OR Quart 3 3.0 3.1 3.0 p Value 0.028 0.34 0.050 95% CI of 1.1 0.31 1.00 OR Quart3 8.2 30 8.9 OR Quart 4 6.6 6.3 7.8 p Value 8.5E−5 0.092 9.8E−5 95% CI of 2.6 0.74 2.8 OR Quart4 17 53 22 Coagulation factor VII sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 3.72 7.55 4.03 13.2 3.86 7.85 Average 6.34 11.8 7.00 16.5 6.29 10.9 Stdev 7.90 11.2 8.33 15.3 7.90 9.42 p(t-test) 0.0011 0.0029 0.0069 Min 0.00408 0.348 0.00408 0.348 0.00408 0.682 Max 48.9 47.7 48.9 47.7 48.9 36.7 n (Samp) 139 35 165 8 112 30 n (Patient) 139 35 165 8 112 30 At Enrollment sCr or UO sCr only UO only AUC 0.67 0.72 0.67 SE 0.054 0.10 0.059 p 0.0017 0.038 0.0031 nCohort 1 139 165 112 nCohort 2 35 8 30 Cutoff 1 4.79 6.05 4.79 Sens 1 71% 75% 70% Spec 1 57% 65% 57% Cutoff 2 2.33 5.29 2.33 Sens 2 80% 88% 80% Spec 2 40% 58% 40% Cutoff 3 1.01 0.313 1.24 Sens 3 91% 100%  90% Spec 3 18%  3% 23% Cutoff 4 7.01 7.52 7.27 Sens 4 54% 50% 57% Spec 4 71% 70% 71% Cutoff 5 9.02 10.2 8.49 Sens 5 43% 50% 43% Spec 5 81% 80% 80% Cutoff 6 15.7 18.7 14.3 Sens 6 31% 50% 33% Spec 6 91% 90% 90% OR Quart 2 0.97 0 0.75 p Value 0.97 na 0.69 95% CI of 0.26 na 0.18 OR Quart2 3.6 na 3.1 OR Quart 3 2.3 3.1 1.8 p Value 0.16 0.33 0.36 95% CI of 0.71 0.31 0.52 OR Quart3 7.4 32 6.1 OR Quart 4 3.9 4.2 3.4 p Value 0.017 0.21 0.040 95% CI of 1.3 0.45 1.1 OR Quart4 12 39 11 Insulin-like growth factor-binding protein 7 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 51.1 131 57.2 306 54.4 131 Average 73.2 213 90.2 295 76.6 209 Stdev 75.7 221 115 240 78.9 217 p(t-test) 1.7E−16 1.7E−8 3.1E−12 Min 1.06 20.4 1.06 23.1 1.06 20.4 Max 533 1250 1250 694 533 1250 n (Samp) 294 61 340 12 215 55 n (Patient) 294 61 340 12 215 55 At Enrollment sCr or UO sCr only UO only AUC 0.77 0.76 0.76 SE 0.037 0.082 0.040 p 1.3E−12 0.0015 3.9E−11 nCohort 1 294 340 215 nCohort 2 61 12 55 Cutoff 1 73.6 88.9 73.6 Sens 1 70% 75% 71% Spec 1 67% 69% 64% Cutoff 2 55.8 39.0 61.3 Sens 2 80% 83% 80% Spec 2 55% 35% 55% Cutoff 3 38.2 23.1 38.4 Sens 3 90% 92% 91% Spec 3 38% 20% 38% Cutoff 4 82.8 90.1 85.1 Sens 4 67% 67% 65% Spec 4 70% 70% 70% Cutoff 5 102 120 104 Sens 5 59% 67% 58% Spec 5 80% 80% 80% Cutoff 6 150 199 146 Sens 6 41% 58% 44% Spec 6 90% 90% 90% OR Quart 2 1.6 0.49 2.4 p Value 0.40 0.57 0.16 95% CI of 0.51 0.044 0.70 OR Quart2 5.2 5.6 8.2 OR Quart 3 3.1 0.49 3.8 p Value 0.038 0.57 0.027 95% CI of 1.1 0.044 1.2 OR Quart3 9.0 5.6 12 OR Quart 4 10 4.3 12 p Value 4.9E−6  0.070 1.6E−5  95% CI of 3.8 0.89 3.8 OR Quart4 28 21 36

TABLE 12 Comparison of marker levels in enroll EDTA samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0 or R within 48 hrs) and in enroll EDTA samples collected from Cohort 2 (subjects reaching RIFLE stage I or F within 48 hrs). Enroll samples from patients already at stage I or F were included in Cohort 2. Cancer Antigen 19-9 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 0.228 0.552 nd nd 0.228 0.452 Average 0.462 0.989 nd nd 0.503 0.942 Stdev 0.734 1.34 nd nd 0.784 1.41 p(t-test) 0.020 nd nd 0.089 Min 1.00E−9 0.0291 nd nd 1.00E−9 0.0291 Max 5.30 5.26 nd nd 5.30 5.26 n (Samp) 78 20 nd nd 67 17 n (Patient) 78 20 nd nd 67 17 At Enrollment sCr or UO sCr only UO only AUC 0.70 nd 0.65 SE 0.071 nd 0.079 p 0.0042 nd 0.054 nCohort 1 78 nd 67 nCohort 2 20 nd 17 Cutoff 1 0.332 nd 0.259 Sens 1 70% nd 71% Spec 1 68% nd 54% Cutoff 2 0.257 nd 0.228 Sens 2 80% nd 82% Spec 2 56% nd 51% Cutoff 3 0.147 nd 0.134 Sens 3 90% nd 94% Spec 3 32% nd 28% Cutoff 4 0.361 nd 0.523 Sens 4 65% nd 47% Spec 4 71% nd 70% Cutoff 5 0.633 nd 0.652 Sens 5 35% nd 29% Spec 5 81% nd 81% Cutoff 6 1.34 nd 1.52 Sens 6 15% nd 12% Spec 6 91% nd 91% OR Quart 2 4.4 nd 1.6 p Value 0.20 nd 0.64 95% CI of 0.45 nd 0.24 OR Quart2 42 nd 11 OR Quart 3 12 nd 4.8 p Value 0.028 nd 0.075 95% CI of 1.3 nd 0.85 OR Quart3 100 nd 26 OR Quart 4 8.9 nd 3.0 p Value 0.049 nd 0.23 95% CI of 1.0 nd 0.51 OR Quart4 79 nd 17 C-X-C motif chemokine 6 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 23.9 29.6 24.0 42.6 21.8 28.8 Average 38.1 38.9 37.0 51.3 38.1 34.3 Stdev 49.2 32.2 45.9 43.2 52.2 20.1 p(t-test) 0.95 0.43 0.79 Min 4.02 9.69 4.02 9.69 4.02 12.3 Max 311 144 311 144 311 88.5 n (Samp) 58 18 69 7 50 14 n (Patient) 58 18 69 7 50 14 At Enrollment sCr or UO sCr only UO only AUC 0.57 0.67 0.59 SE 0.079 0.12 0.089 p 0.35 0.14 0.30 nCohort 1 58 69 50 nCohort 2 18 7 14 Cutoff 1 23.3 39.7 23.3 Sens 1 72% 71% 71% Spec 1 48% 74% 52% Cutoff 2 16.7 26.0 16.7 Sens 2 83% 86% 86% Spec 2 33% 59% 36% Cutoff 3 10.5 8.88 15.8 Sens 3 94% 100%  93% Spec 3 17%  7% 32% Cutoff 4 38.9 38.9 38.7 Sens 4 44% 71% 43% Spec 4 71% 71% 70% Cutoff 5 46.0 45.4 46.0 Sens 5 17% 29% 14% Spec 5 81% 81% 80% Cutoff 6 66.6 66.6 61.7 Sens 6 11% 14%  7% Spec 6 91% 91% 90% OR Quart 2 1.4 0 5.0 p Value 0.68 na 0.17 95% CI of 0.27 na 0.49 OR Quart2 7.4 na 51 OR Quart 3 3.1 4.8 9.0 p Value 0.15 0.18 0.057 95% CI of 0.66 0.48 0.94 OR Quart3 15 48 87 OR Quart 4 1.4 2.1 3.5 p Value 0.68 0.55 0.31 95% CI of 0.27 0.18 0.32 OR Quart4 7.4 26 37 Coagulation factor VII sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 287 225 280 173 276 268 Average 320 239 308 201 298 250 Stdev 182 142 179 90.2 159 149 p(t-test) 0.014 0.077 0.14 Min 2.08 12.2 2.08 75.6 35.7 12.2 Max 950 571 950 380 809 571 n (Samp) 140 36 166 9 112 31 n (Patient) 140 36 166 9 112 31 At Enrollment sCr or UO sCr only UO only AUC 0.37 0.32 0.42 SE 0.055 0.10 0.060 p 0.020 0.069 0.18 nCohort 1 140 166 112 nCohort 2 36 9 31 Cutoff 1 153 158 153 Sens 1 72% 78% 71% Spec 1 19% 22% 21% Cutoff 2 102 129 102 Sens 2 81% 89% 81% Spec 2  9% 14% 10% Cutoff 3 64.8 74.8 64.8 Sens 3 92% 100%  90% Spec 3  4%  7% 3 % Cutoff 4 376 368 361 Sens 4 19% 11% 23% Spec 4 71% 71% 71% Cutoff 5 463 458 456 Sens 5  6%  0%  6% Spec 5 80% 80% 80% Cutoff 6 574 537 526 Sens 6  0%  0%  6% Spec 6 90% 90% 90% OR Quart 2 1.4 >2.1 1.2 p Value 0.56 <0.55 0.77 95% CI of 0.44 >0.18 0.38 OR Quart2 4.5 na 3.7 OR Quart 3 1.4 >3.2 0.67 p Value 0.56 <0.32 0.53 95% CI of 0.44 >0.32 0.19 OR Quart3 4.5 na 2.3 OR Quart 4 3.0 >4.5 1.9 p Value 0.047 <0.19 0.25 95% CI of 1.0 >0.48 0.64 OR Quart4 8.6 na 5.7 Insulin-like growth factor-binding protein 7 sCr or UO sCr only UO only Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 Median 73.2 97.8 nd nd 73.5 96.3 Average 75.2 124 nd nd 78.8 120 Stdev 31.9 95.9 nd nd 32.8 100.0 p(t-test) 2.3E−4 nd nd 0.0049 Min 18.6 43.7 nd nd 38.1 43.7 Max 188 437 nd nd 188 437 n (Samp) 78 20 nd nd 67 17 n (Patient) 78 20 nd nd 67 17 At Enrollment sCr or UO sCr only UO only AUC 0.68 nd 0.63 SE 0.072 nd 0.079 p 0.014 nd 0.11 nCohort 1 78 nd 67 nCohort 2 20 nd 17 Cutoff 1 66.7 nd 57.2 Sens 1 70% nd 71% Spec 1 46% nd 34% Cutoff 2 55.2 nd 53.3 Sens 2 80% nd 82% Spec 2 33% nd 28% Cutoff 3 52.0 nd 49.8 Sens 3 90% nd 94% Spec 3 23% nd 15% Cutoff 4 84.3 nd 86.1 Sens 4 60% nd 59% Spec 4 71% nd 70% Cutoff 5 91.7 nd 97.1 Sens 5 60% nd 47% Spec 5 81% nd 81% Cutoff 6 114 nd 128 Sens 6 40% nd 24% Spec 6 91% nd 91% OR Quart 2 1.8 nd 1.4 p Value 0.48 nd 0.68 95% CI of 0.37 nd 0.27 OR Quart2 8.3 nd 7.3 OR Quart 3 0.30 nd 0.63 p Value 0.32 nd 0.64 95% CI of 0.029 nd 0.094 OR Quart3 3.2 nd 4.2 OR Quart 4 5.5 nd 3.7 p Value 0.021 nd 0.089 95% CI of 1.3 nd 0.82 OR Quart4 23 nd 17

Example 7 Kidney Injury Markers for Evaluating Mortality Risk in Patients

Patients from the intensive care unit (ICU) were enrolled in the following study. Each patient was classified by kidney status as non-injury (0), risk of injury (R), injury (I), and failure (F) according to the maximum stage reached within 48 hours of enrollment as determined by the RIFLE criteria. EDTA anti-coagulated blood samples (10 mL) and a urine samples (25-30 mL) were collected from each patient at the time of enrollment into the study. Markers were each measured by standard immunoassay methods using commercially available assay reagents in the urine samples and the plasma component of the blood samples collected.

The patient population was segregated based on the marker concentrations using threshold values which divided the population into thirds (“tertiles”). Patients with marker concentrations in the lower, middle, and upper third comprise the first, second, and third tertiles, respectively. The relative risk of AKI-related mortality within 7, 14, and 28 days was calculated for the second and third tertiles, relative to a value of 1 for the first tertile, as indicated in the following table. “AKI-related mortality” or “AKI-related death” was defined as death accompanied by a minimum RIFLE stage of R.

TABLE 13 Relative risk of AKI-related death within 7, 14, and 28 days from enrollment for the third tertile compared to the first tertile of marker concentrations. Relative Risk Total Total Number for Third Number of of AKI- Marker Tertile p Patients related Deaths AKI-Related Death Insulin-like growth factor- 5.5 0.02 355 16 within 7 Days after binding protein 7 enrollment C-X-C motif chemokine 6 3.0 0.09 356 16 AKI-Related Death Insulin-like growth factor- 6.5 0.01 355 20 within 14 Days after binding protein 7 enrollment C-X-C motif chemokine 6 4.0 0.03 356 20 AKI-Related Death Insulin-like growth factor- 4.7 0.01 355 22 within 28 Days after binding protein 7 enrollment C-X-C motif chemokine 6 3.0 0.05 356 22

While the invention has been described and exemplified in sufficient detail for those skilled in this art to make and use it, various alternatives, modifications, and improvements should be apparent without departing from the spirit and scope of the invention. The examples provided herein are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention. Modifications therein and other uses will occur to those skilled in the art. These modifications are encompassed within the spirit of the invention and are defined by the scope of the claims.

It will be readily apparent to a person skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention.

All patents and publications mentioned in the specification are indicative of the levels of those of ordinary skill in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein. Thus, for example, in each instance herein any of the terms “comprising”, “consisting essentially of” and “consisting of” may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.

Other embodiments are set forth within the following claims. 

1. A method for evaluating biomarker levels in a body fluid sample from a subject, comprising: obtaining a urine sample from a subject selected for evaluation based on a determination that the subject is at risk of a future or current acute renal injury; performing one or more assays configured to detect one or more biomarkers selected from the group consisting of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine 13 by introducing the urine sample obtained from the subject into an assay instrument which (i) for each analyte binding assay performed, contacts all or a portion of the urine sample with a binding reagent which specifically binds for detection the kidney injury marker which is assayed, and (ii) generates one or more assay results indicative of binding of each biomarker which is assayed to its respective binding reagent and displays the assay results generated in human readable form; and correlating the assay result(s) generated by the assay instrument to the renal status of the subject.
 2. A method according to claim 1, wherein said correlation step the subject is selected for evaluation based on a determination that the subject is in need of risk stratification, diagnosis, staging, prognosis, classifying and monitoring of the renal status of the subject.
 3. A method according to claim 1, wherein the subject is selected for evaluation based on a determination that the subject is at risk of a future acute renal injury.
 4. A method according to claim 3, wherein the subject is selected for evaluation based on a determination that the subject is at risk of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF).
 5. A method according to claim 1, wherein said assay results comprise at least 2, 3, 4, or 5 of: a measured concentration of Coagulation factor VII, a measured concentration of CA19-9, a measured concentration of Insulin-like growth factor-binding protein 7, a measured concentration of C—X—C motif chemokine 6, and a measured concentration of C—C motif chemokine
 13. 6. A method according to claim 5, wherein a plurality of assay results are combined using a function that converts the plurality of assay results into a single composite result.
 7. (canceled)
 8. A method according to claim 3, wherein the subject is selected for evaluation based on a determination that the subject is at risk of a future acute renal injury within 30 days of the time at which the urine sample is obtained from the subject.
 9. A method according to claim 8, wherein the subject is selected for evaluation based on a determination that the subject is at risk of a future acute renal injury within a period selected from the group consisting of 21 days, 14 days, 7 days, 5 days, 96 hours, 72 hours, 48 hours, 36 hours, 24 hours, and 12 hours.
 10. A method according to claim 1, wherein the subject is selected for evaluation of renal status based on the pre-existence in the subject of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF.
 11. A method according to claim 1, wherein the subject is selected for evaluation of renal status based on an existing diagnosis of one or more of congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, glomerular filtration below the normal range, cirrhosis, serum creatinine above the normal range, sepsis, injury to renal function, reduced renal function, or ARF, or based on undergoing or having undergone major vascular surgery, coronary artery bypass, or other cardiac surgery, or based on exposure to NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin.
 12. A method according to claim 1, wherein each assay is an immunoassay performed by (i) introducing the urine sample into an assay device comprising at least one of which binds to a biomarker which is assayed, and (ii) generating an assay result indicative of binding of each biomarker to its respective antibody.
 13. A method according to claim 1, wherein said correlating step comprises assessing whether or not renal function is improving or worsening in a subject who has suffered from an injury to renal function, reduced renal function, or ARF based on the assay result(s). 14-23. (canceled)
 24. A method according to claim 1, wherein said one or more future changes in renal status comprise one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF) within 72 hours of the time at which the body fluid sample is obtained.
 25. A method according to claim 24, wherein said correlating step comprises correlating the assay results to a likelihood of one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF) within 48 hours of the time at which the body fluid sample is obtained.
 26. A method according to claim 24, wherein said correlating step comprises correlating the assay results to a likelihood of one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF) within 24 hours of the time at which the body fluid sample is obtained.
 27. A method according to claim 1, wherein the subject is in RIFLE stage 0 or R.
 28. A method according to claim 27, wherein the subject is in RIFLE stage
 0. 29-32. (canceled)
 33. A method according to claim 27, wherein the subject is in RIFLE stage R.
 34. (canceled)
 35. A method according to claim 1, wherein the subject is in RIFLE stage 0, R, or I.
 36. A method according to claim 35, wherein the subject is in RIFLE stage I. 37-54. (canceled)
 55. A method according to claim 1, wherein the subject is not in acute renal failure. 56-99. (canceled)
 100. A method according to claim 1, wherein said method comprises performing assays that detect one, two or three, or more of Coagulation factor VII, CA19-9, Insulin-like growth factor-binding protein 7, C—X—C motif chemokine 6, and C—C motif chemokine
 13. 101-108. (canceled) 